lørdag den 21. oktober 2023 kl. 15.54.17 UTC+2 skrev John Larkin:
> On Fri, 20 Oct 2023 07:50:14 -0700 (PDT), Fred Bloggs 
> <bloggs.fred...@gmail.com> wrote:
> >On Friday, October 20, 2023 at 10:42:42?AM UTC-4, Glen Walpert wrote: 
> >> On Thu, 19 Oct 2023 20:01:07 -0400, Joe Gwinn wrote: 
> >> 
> >> > On Thu, 19 Oct 2023 16:37:39 -0700, john larkin <j...@650pot.com> wrote: 
> >> > 
> >> >>On Thu, 19 Oct 2023 13:49:12 -0700, John Robertson <j...@flippers.com> 
> >> >>wrote: 
> >> >> 
> >> >>>I'd like to verify that 74F##(#) family can replace the 74##(#) chips 
> >> >>>which are getting rather expensive or of unknown (?) quality if one is 
> >> >>>second sourcing them from folks like Unicorn, or eBay (shudder). 
> >> >>> 
> >> >>>I am well aware the 74LS has may replacements including the 74ALS, 
> >> >>>74HCT, and others, but they only fan-out to 10 LS gates or 1 original 
> >> >>>gates. 
> >> >> 
> >> >>74HC or 74HCT should drive many old 74xx parts. 
> >> >> 
> >> >>7400s only sourced about 1 mA at their inputs, and LS was 0.4 mA max. 
> >> >>A 74HC or HCT should easily drive five 74xx and scores of 74LS gates. 
> >> >> 
> >> >>The hc/hct parts will be faster than the old TTLs, which could be a 
> >> >>problem with old hairball logic. 
> >> > 
> >> > Yes. I've had to interface new kit to very old kit. The answer was 
> >> > Schmitt trigger for signals coming into new, and RC filters going into 
> >> > old. 
> >> > 
> >> > 
> >> > Joe Gwinn 
> >> > 
> >> I recall some instances of people switching existing TTL designs to HC, 
> >> and discovering that termination or better termination was required on 
> >> clock and data lines. The RC filter should prevent that problem. 
> > 
> >That was the 3x faster output rise/fall time doing that. 
> > 
> >> 
> >> I have a box of old IC's containing a bunch of 74xx parts in original Jim- 
> >> Pak or Active Electronics packaging, mostly unopened, I could send the 
> >> 74xx parts or the entire box for you to sort including various counters, 
> >> shift registers, PLL's, more LS than plain TTL but contents largely 
> >> unremembered, possibly old memory. The empty space is now more valuable 
> >> than the parts to me, and I would rather pay postage to someone who can 
> >> use them than throw them out. 
> >> 
> >> Glen 
> >> >>>I have older games that need reliable 74## and won't work reliably with 
> >> >>>the lower fan-out stuff. 
> >> >>> 
> >> >>>I have a Fairchild FAST DATA BOOK, but it doesn't actually say anywhere 
> >> >>>I've read so far about how compatible it is with the original TTL 
> >> >>>fan-outs. They do say that the F family are more susceptible to static 
> >> >>>than 74S or 74LS so perhaps I will look at 74S in place of the 
> >> >>>originals if they have a similar fan-out. 
> >> >>> 
> >> >>>Suggestions welcome! 
> >> >>> 
> >> >>>John :-#)#
> In the early days of AC logic, I was amazed to see well sub-nS edges 
> from cheap parts. 
> 
> Some of the Tiny cmos parts are crazy fast. 
> 
> https://www.dropbox.com/scl/fi/iugv8wzmh3ie9zzmv8vpi/NC7SV74_2.JPG?rlkey=tkdj4ire4e92wixk57omm8k2o&dl=0

and if you stick that in a 40 year old hairball, it'll get "interesting"

On Sunday, October 22, 2023 at 12:54:17 AM UTC+11, John Larkin wrote:
> On Fri, 20 Oct 2023 07:50:14 -0700 (PDT), Fred Bloggs 
> <bloggs.fred...@gmail.com> wrote:
> >On Friday, October 20, 2023 at 10:42:42?AM UTC-4, Glen Walpert wrote: 
> >> On Thu, 19 Oct 2023 20:01:07 -0400, Joe Gwinn wrote: 
> >> 
> >> > On Thu, 19 Oct 2023 16:37:39 -0700, john larkin <j...@650pot.com> wrote: 
> >> > 
> >> >>On Thu, 19 Oct 2023 13:49:12 -0700, John Robertson <j...@flippers.com> 
> >> >>wrote: 
> >> >> 
> >> >>>I'd like to verify that 74F##(#) family can replace the 74##(#) chips 
> >> >>>which are getting rather expensive or of unknown (?) quality if one is 
> >> >>>second sourcing them from folks like Unicorn, or eBay (shudder). 
> >> >>> 
> >> >>>I am well aware the 74LS has may replacements including the 74ALS, 
> >> >>>74HCT, and others, but they only fan-out to 10 LS gates or 1 original 
> >> >>>gates. 
> >> >> 
> >> >>74HC or 74HCT should drive many old 74xx parts. 
> >> >> 
> >> >>7400s only sourced about 1 mA at their inputs, and LS was 0.4 mA max. 
> >> >>A 74HC or HCT should easily drive five 74xx and scores of 74LS gates. 
> >> >> 
> >> >>The hc/hct parts will be faster than the old TTLs, which could be a 
> >> >>problem with old hairball logic. 
> >> > 
> >> > Yes. I've had to interface new kit to very old kit. The answer was 
> >> > Schmitt trigger for signals coming into new, and RC filters going into 
> >> > old. 
> >> > 
> >> > 
> >> > Joe Gwinn 
> >> > 
> >> I recall some instances of people switching existing TTL designs to HC, 
> >> and discovering that termination or better termination was required on 
> >> clock and data lines. The RC filter should prevent that problem. 
> > 
> >That was the 3x faster output rise/fall time doing that. 
> > 
> >> 
> >> I have a box of old IC's containing a bunch of 74xx parts in original Jim- 
> >> Pak or Active Electronics packaging, mostly unopened, I could send the 
> >> 74xx parts or the entire box for you to sort including various counters, 
> >> shift registers, PLL's, more LS than plain TTL but contents largely 
> >> unremembered, possibly old memory. The empty space is now more valuable 
> >> than the parts to me, and I would rather pay postage to someone who can 
> >> use them than throw them out. 
> >> 
> >> Glen 
> >> >>>I have older games that need reliable 74## and won't work reliably with 
> >> >>>the lower fan-out stuff. 
> >> >>> 
> >> >>>I have a Fairchild FAST DATA BOOK, but it doesn't actually say anywhere 
> >> >>>I've read so far about how compatible it is with the original TTL 
> >> >>>fan-outs. They do say that the F family are more susceptible to static 
> >> >>>than 74S or 74LS so perhaps I will look at 74S in place of the 
> >> >>>originals if they have a similar fan-out. 
> >> >>> 
> >> >>>Suggestions welcome! 
> >> >>> 
> >> >>>John :-#)#
> In the early days of AC logic, I was amazed to see well sub-nS edges 
> from cheap parts. 
> 
> Some of the Tiny cmos parts are crazy fast. 
> 
> https://www.dropbox.com/scl/fi/iugv8wzmh3ie9zzmv8vpi/NC7SV74_2.JPG?rlkey=tkdj4ire4e92wixk57omm8k2o&dl=0

But they don't drive transmission lines well. The charm of ECL and ECLinPs and LVDS is that it does.

If you can confine your logic inside a single big fast programmable logic device, this doesn't matter so much, but fast edges don't stay fast for long if you stick them into unterminated transmission lines, and reflected fast edges can play havoc.

-- 
Bill Sloman, Sydney

On Fri, 20 Oct 2023 07:50:14 -0700 (PDT), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:

>On Friday, October 20, 2023 at 10:42:42?AM UTC-4, Glen Walpert wrote:
>> On Thu, 19 Oct 2023 20:01:07 -0400, Joe Gwinn wrote: 
>> 
>> > On Thu, 19 Oct 2023 16:37:39 -0700, john larkin <j...@650pot.com> wrote: 
>> > 
>> >>On Thu, 19 Oct 2023 13:49:12 -0700, John Robertson <j...@flippers.com> 
>> >>wrote: 
>> >> 
>> >>>I'd like to verify that 74F##(#) family can replace the 74##(#) chips 
>> >>>which are getting rather expensive or of unknown (?) quality if one is 
>> >>>second sourcing them from folks like Unicorn, or eBay (shudder). 
>> >>> 
>> >>>I am well aware the 74LS has may replacements including the 74ALS, 
>> >>>74HCT, and others, but they only fan-out to 10 LS gates or 1 original 
>> >>>gates. 
>> >> 
>> >>74HC or 74HCT should drive many old 74xx parts. 
>> >> 
>> >>7400s only sourced about 1 mA at their inputs, and LS was 0.4 mA max. 
>> >>A 74HC or HCT should easily drive five 74xx and scores of 74LS gates. 
>> >> 
>> >>The hc/hct parts will be faster than the old TTLs, which could be a 
>> >>problem with old hairball logic. 
>> > 
>> > Yes. I've had to interface new kit to very old kit. The answer was 
>> > Schmitt trigger for signals coming into new, and RC filters going into 
>> > old. 
>> > 
>> > 
>> > Joe Gwinn 
>> >
>> I recall some instances of people switching existing TTL designs to HC, 
>> and discovering that termination or better termination was required on 
>> clock and data lines. The RC filter should prevent that problem.
>
>That was the 3x faster output rise/fall time doing that.
> 
>> 
>> I have a box of old IC's containing a bunch of 74xx parts in original Jim- 
>> Pak or Active Electronics packaging, mostly unopened, I could send the 
>> 74xx parts or the entire box for you to sort including various counters, 
>> shift registers, PLL's, more LS than plain TTL but contents largely 
>> unremembered, possibly old memory. The empty space is now more valuable 
>> than the parts to me, and I would rather pay postage to someone who can 
>> use them than throw them out. 
>> 
>> Glen
>> >>>I have older games that need reliable 74## and won't work reliably with 
>> >>>the lower fan-out stuff. 
>> >>> 
>> >>>I have a Fairchild FAST DATA BOOK, but it doesn't actually say anywhere 
>> >>>I've read so far about how compatible it is with the original TTL 
>> >>>fan-outs. They do say that the F family are more susceptible to static 
>> >>>than 74S or 74LS so perhaps I will look at 74S in place of the 
>> >>>originals if they have a similar fan-out. 
>> >>> 
>> >>>Suggestions welcome! 
>> >>> 
>> >>>John :-#)#

In the early days of AC logic, I was amazed to see well sub-nS edges
from cheap parts.

Some of the Tiny cmos parts are crazy fast.

https://www.dropbox.com/scl/fi/iugv8wzmh3ie9zzmv8vpi/NC7SV74_2.JPG?rlkey=tkdj4ire4e92wixk57omm8k2o&dl=0

On Friday, October 20, 2023 at 1:20:13 PM UTC-4, John Robertson wrote:
> On 2023/10/20 10:14 a.m., Fred Bloggs wrote: 
> > On Friday, October 20, 2023 at 1:05:10 PM UTC-4, John Robertson wrote: 
> >> On 2023/10/20 7:47 a.m., Fred Bloggs wrote: 
> >>> On Thursday, October 19, 2023 at 4:49:40 PM UTC-4, John Robertson wrote: 
> >>>> I'd like to verify that 74F##(#) family can replace the 74##(#) chips 
> >>>> which are getting rather expensive or of unknown (?) quality if one is 
> >>>> second sourcing them from folks like Unicorn, or eBay (shudder). 
> >>>> 
> >>>> I am well aware the 74LS has may replacements including the 74ALS, 
> >>>> 74HCT, and others, but they only fan-out to 10 LS gates or 1 original 
> >>>> gates. 
> >>>> 
> >>>> I have older games that need reliable 74## and won't work reliably with 
> >>>> the lower fan-out stuff. 
> >>>> 
> >>>> I have a Fairchild FAST DATA BOOK, but it doesn't actually say anywhere 
> >>>> I've read so far about how compatible it is with the original TTL 
> >>>> fan-outs. They do say that the F family are more susceptible to static 
> >>>> than 74S or 74LS so perhaps I will look at 74S in place of the originals 
> >>>> if they have a similar fan-out. 
> >>> 
> >>> FAST logic is superior in all respects, is totally compatible with 74 TTL, uses way less power, and the Tpd is about 1/5 that of TTL. 
> >>> 
> >>> It's overkill iow. 
> >>> 
> >>> The HC drives TTL, but the question is does TTL drive it. Technically, no it doesn't, and that's what HCT is about. 
> >>> 
> >>> If you can eyeball the circuit enough to determine the specific fan-ins/outs then LS should be the cheapest option, and the least problem because of identical I/O performance VIL VIH VOL VOH, mins/maxs etc. 
> >>> 
> >>> Logic families were all designed to be compatible with itself. They will also, somewhere in the data book, define a unit fan H/L in uA or mA. That tells you all you need to know to translate loading/drive mixed with another family. 
> >> Thanks Fred, I figured 74F should work - interesting that another poster 
> >> mentioned is is essentially 74AS which widens the available sources as well. 
> > 
> > FAST (Fairchild Advanced Schottky TTL)
> Dang, it says that right on the cover! 
> 
> I need to RTFM obviously - COVER to cover...

Don't make any assumptions about FAST being the same as AS. I recall they had some clear differences.  Otherwise, why call it anything other than AS?  

-- 

  Rick C.

  - Get 1,000 miles of free Supercharging
  - Tesla referral code - https://ts.la/richard11209

On 21/10/2023 3:52 am, John Robertson wrote:
> Hi Chris,
> 
> On 2023/10/20 5:31 a.m., Chris Jones wrote:
>> On 20/10/2023 7:49 am, John Robertson wrote:
>>> I'd like to verify that 74F##(#) family can replace the 74##(#) chips 
>>> which are getting rather expensive or of unknown (?) quality if one 
>>> is second sourcing them from folks like Unicorn, or eBay (shudder).
>>>
>>> I am well aware the 74LS has may replacements including the 74ALS, 
>>> 74HCT, and others, but they only fan-out to 10 LS gates or 1 original 
>>> gates.
>>>
>>> I have older games that need reliable 74## and won't work reliably 
>>> with the lower fan-out stuff.
>>>
>>> I have a Fairchild FAST DATA BOOK, but it doesn't actually say 
>>> anywhere I've read so far about how compatible it is with the 
>>> original TTL fan-outs. They do say that the F family are more 
>>> susceptible to static than 74S or 74LS so perhaps I will look at 74S 
>>> in place of the originals if they have a similar fan-out.
>>>
>>> Suggestions welcome!
>>>
>>> John :-#)#
>>
>> You should post your specific list of wanted parts here, or on the 
>> EEVBLOG forum.
> 
> I use pretty service much the entire 74## family in my board repairs. 
> Fixing the very first arcade games (Nutting's Computer Space) to use TTL 
> through to modern stuff - which has other supply issues of course.
> 
>>
>> I have many 74xx parts (and 93xx too) (NOS and/or working used) that I 
>> will probably never use in a new design, and almost none of the things 
>> I repair require them either.
> 
> If you are willing to ship them to me, I'd be happy to refund your 
> postage (parcel post) - my shop address is below.

At this point I don't think I want to send you everything I have 
(sorry!), but if you post a list of the ones you have low stock of and 
which you use, then I might send you those, if I have them.

Chris

On Fri, 20 Oct 2023 09:52:08 -0700, John Robertson <jrr@flippers.com>
wrote:

>On 2023/10/19 2:37 p.m., boB wrote:
>> On Thu, 19 Oct 2023 13:49:12 -0700, John Robertson <jrr@flippers.com>
>> wrote:
>> 
>>> I'd like to verify that 74F##(#) family can replace the 74##(#) chips
>>> which are getting rather expensive or of unknown (?) quality if one is
>>> second sourcing them from folks like Unicorn, or eBay (shudder).
>>>
>>> I am well aware the 74LS has may replacements including the 74ALS,
>>> 74HCT, and others, but they only fan-out to 10 LS gates or 1 original
>>> gates.
>>>
>>> I have older games that need reliable 74## and won't work reliably with
>>> the lower fan-out stuff.
>>>
>>> I have a Fairchild FAST DATA BOOK, but it doesn't actually say anywhere
>>> I've read so far about how compatible it is with the original TTL
>>> fan-outs. They do say that the F family are more susceptible to static
>>> than 74S or 74LS so perhaps I will look at 74S in place of the originals
>>> if they have a similar fan-out.
>>>
>>> Suggestions welcome!
>>>
>>> John :-#)#
>> 
>> 
>> How about 74HC  parts ?
>
>Too many problems when interfacing HC with older TTL. Both HC and HCT 
>are essentially LS in fan-out and their output voltages don't work in a 
>number of circuits. I was servicing one game where the board designer 
>substituted HCT in place of the original LS and the HCT chips would not 
>drive the optos correctly. Took a while to track that down as I had 
>assumed the board redesign had been done correctly...
>
>> 
>> That's pretty much what I have been using for the last several years
>> 
>> boB
>
>Sometimes they work, often they introduce new problems. And if one is 
>dealing with a component level board with several issues adding a new 
>problem to the mix isn't optimal.
>
>John :-#(#

That's an interesting take and valid points I'm sure.

Where I use HC parts, thare are no old TTL parts connected to the HC
parts so they work fine... So far, so good anyway :)

boB

On 2023/10/20 10:14 a.m., Fred Bloggs wrote:
> On Friday, October 20, 2023 at 1:05:10 PM UTC-4, John Robertson wrote:
>> On 2023/10/20 7:47 a.m., Fred Bloggs wrote:
>>> On Thursday, October 19, 2023 at 4:49:40 PM UTC-4, John Robertson wrote:
>>>> I'd like to verify that 74F##(#) family can replace the 74##(#) chips
>>>> which are getting rather expensive or of unknown (?) quality if one is
>>>> second sourcing them from folks like Unicorn, or eBay (shudder).
>>>>
>>>> I am well aware the 74LS has may replacements including the 74ALS,
>>>> 74HCT, and others, but they only fan-out to 10 LS gates or 1 original
>>>> gates.
>>>>
>>>> I have older games that need reliable 74## and won't work reliably with
>>>> the lower fan-out stuff.
>>>>
>>>> I have a Fairchild FAST DATA BOOK, but it doesn't actually say anywhere
>>>> I've read so far about how compatible it is with the original TTL
>>>> fan-outs. They do say that the F family are more susceptible to static
>>>> than 74S or 74LS so perhaps I will look at 74S in place of the originals
>>>> if they have a similar fan-out.
>>>
>>> FAST logic is superior in all respects, is totally compatible with 74 TTL, uses way less power, and the Tpd is about 1/5 that of TTL.
>>>
>>> It's overkill iow.
>>>
>>> The HC drives TTL, but the question is does TTL drive it. Technically, no it doesn't, and that's what HCT is about.
>>>
>>> If you can eyeball the circuit enough to determine the specific fan-ins/outs then LS should be the cheapest option, and the least problem because of identical I/O performance VIL VIH VOL VOH, mins/maxs etc.
>>>
>>> Logic families were all designed to be compatible with itself. They will also, somewhere in the data book, define a unit fan H/L in uA or mA. That tells you all you need to know to translate loading/drive mixed with another family.
>> Thanks Fred, I figured 74F should work - interesting that another poster
>> mentioned is is essentially 74AS which widens the available sources as well.
> 
> FAST (Fairchild Advanced Schottky TTL)

Dang, it says that right on the cover!

I need to RTFM obviously - COVER to cover...

John ;-#)#
-- 
(Please post followups or tech inquiries to the USENET newsgroup)
                      John's Jukes Ltd.
        #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
          (604)872-5757 (Pinballs, Jukes, Video Games)
                      www.flippers.com
        "Old pinballers never die, they just flip out."

On Friday, October 20, 2023 at 1:05:10 PM UTC-4, John Robertson wrote:
> On 2023/10/20 7:47 a.m., Fred Bloggs wrote: 
> > On Thursday, October 19, 2023 at 4:49:40 PM UTC-4, John Robertson wrote: 
> >> I'd like to verify that 74F##(#) family can replace the 74##(#) chips 
> >> which are getting rather expensive or of unknown (?) quality if one is 
> >> second sourcing them from folks like Unicorn, or eBay (shudder). 
> >> 
> >> I am well aware the 74LS has may replacements including the 74ALS, 
> >> 74HCT, and others, but they only fan-out to 10 LS gates or 1 original 
> >> gates. 
> >> 
> >> I have older games that need reliable 74## and won't work reliably with 
> >> the lower fan-out stuff. 
> >> 
> >> I have a Fairchild FAST DATA BOOK, but it doesn't actually say anywhere 
> >> I've read so far about how compatible it is with the original TTL 
> >> fan-outs. They do say that the F family are more susceptible to static 
> >> than 74S or 74LS so perhaps I will look at 74S in place of the originals 
> >> if they have a similar fan-out. 
> > 
> > FAST logic is superior in all respects, is totally compatible with 74 TTL, uses way less power, and the Tpd is about 1/5 that of TTL. 
> > 
> > It's overkill iow. 
> > 
> > The HC drives TTL, but the question is does TTL drive it. Technically, no it doesn't, and that's what HCT is about. 
> > 
> > If you can eyeball the circuit enough to determine the specific fan-ins/outs then LS should be the cheapest option, and the least problem because of identical I/O performance VIL VIH VOL VOH, mins/maxs etc. 
> > 
> > Logic families were all designed to be compatible with itself. They will also, somewhere in the data book, define a unit fan H/L in uA or mA. That tells you all you need to know to translate loading/drive mixed with another family.
> Thanks Fred, I figured 74F should work - interesting that another poster 
> mentioned is is essentially 74AS which widens the available sources as well. 

FAST (Fairchild Advanced Schottky TTL) 

> 
> As you say, while HC is not compatible with TTL, and HCT is 'usually', 
> I'm looking for drop-in without having to redesign anything - these are 
> for repairs, not new designs. Repairs need to be done on a timely 
> fashion or customers get annoyed with really high bills for time spent 
> on upgrades so the newer parts will work. 
> 
> I do design some new simple boards and try to use modern TTL that is not 
> being discontinued or there is a huge supply of the parts for future 
> service.
> John :-#)# 
> 
> 
> -- 
> (Please post followups or tech inquiries to the USENET newsgroup) 
> John's Jukes Ltd. 
> #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 
> (604)872-5757 (Pinballs, Jukes, Video Games) 
> www.flippers.com 
> "Old pinballers never die, they just flip out."

On 2023/10/19 2:37 p.m., boB wrote:
> On Thu, 19 Oct 2023 13:49:12 -0700, John Robertson <jrr@flippers.com>
> wrote:
> 
>> I'd like to verify that 74F##(#) family can replace the 74##(#) chips
>> which are getting rather expensive or of unknown (?) quality if one is
>> second sourcing them from folks like Unicorn, or eBay (shudder).
>>
>> I am well aware the 74LS has may replacements including the 74ALS,
>> 74HCT, and others, but they only fan-out to 10 LS gates or 1 original
>> gates.
>>
>> I have older games that need reliable 74## and won't work reliably with
>> the lower fan-out stuff.
>>
>> I have a Fairchild FAST DATA BOOK, but it doesn't actually say anywhere
>> I've read so far about how compatible it is with the original TTL
>> fan-outs. They do say that the F family are more susceptible to static
>> than 74S or 74LS so perhaps I will look at 74S in place of the originals
>> if they have a similar fan-out.
>>
>> Suggestions welcome!
>>
>> John :-#)#
> 
> 
> How about 74HC  parts ?

Too many problems when interfacing HC with older TTL. Both HC and HCT 
are essentially LS in fan-out and their output voltages don't work in a 
number of circuits. I was servicing one game where the board designer 
substituted HCT in place of the original LS and the HCT chips would not 
drive the optos correctly. Took a while to track that down as I had 
assumed the board redesign had been done correctly...

> 
> That's pretty much what I have been using for the last several years
> 
> boB

Sometimes they work, often they introduce new problems. And if one is 
dealing with a component level board with several issues adding a new 
problem to the mix isn't optimal.

John :-#(#

-- 
(Please post followups or tech inquiries to the USENET newsgroup)
                      John's Jukes Ltd.
        #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
          (604)872-5757 (Pinballs, Jukes, Video Games)
                      www.flippers.com
        "Old pinballers never die, they just flip out."

Hi Chris,

On 2023/10/20 5:31 a.m., Chris Jones wrote:
> On 20/10/2023 7:49 am, John Robertson wrote:
>> I'd like to verify that 74F##(#) family can replace the 74##(#) chips 
>> which are getting rather expensive or of unknown (?) quality if one is 
>> second sourcing them from folks like Unicorn, or eBay (shudder).
>>
>> I am well aware the 74LS has may replacements including the 74ALS, 
>> 74HCT, and others, but they only fan-out to 10 LS gates or 1 original 
>> gates.
>>
>> I have older games that need reliable 74## and won't work reliably 
>> with the lower fan-out stuff.
>>
>> I have a Fairchild FAST DATA BOOK, but it doesn't actually say 
>> anywhere I've read so far about how compatible it is with the original 
>> TTL fan-outs. They do say that the F family are more susceptible to 
>> static than 74S or 74LS so perhaps I will look at 74S in place of the 
>> originals if they have a similar fan-out.
>>
>> Suggestions welcome!
>>
>> John :-#)#
> 
> You should post your specific list of wanted parts here, or on the 
> EEVBLOG forum.

I use pretty service much the entire 74## family in my board repairs. 
Fixing the very first arcade games (Nutting's Computer Space) to use TTL 
through to modern stuff - which has other supply issues of course.

> 
> I have many 74xx parts (and 93xx too) (NOS and/or working used) that I 
> will probably never use in a new design, and almost none of the things I 
> repair require them either.

If you are willing to ship them to me, I'd be happy to refund your 
postage (parcel post) - my shop address is below.

Thanks!

John :-#)#

-- 
(Please post followups or tech inquiries to the USENET newsgroup)
                      John's Jukes Ltd.
        #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
          (604)872-5757 (Pinballs, Jukes, Video Games)
                      www.flippers.com
        "Old pinballers never die, they just flip out."