exxos's Atari, Amiga & retro forum

Hey guys,

I know this has been touched on before and I have read the other threads on similar subjects, but those threads are now locked to further posts and I just wanted some confirmation.

I just purchased an ST 16mhz Booster 2021, STF C070789 CPU relocator, 64pin socket and 16mhz capable CPU (pin headers etc I have in spades). This is to go into a 1040 STF C070789-001 Rev C1 with an installed Blitter. I will be doing the required mods/fixes and the motherboard has been fully recapped with a Recapped PSU with upgraded rectifier.

My question is, I currently have KAOS TOS 1.4.2 (English version) installed via 6 x M27C256-10F1 100ns EPROMs - will these EPROMs be fast enough to work with the 16mhz Booster? I don't require the TOS 2.06 decoding etc functions, just the 16mhz CPU acceleration.

Thanks for your help.

If they are genuine 100ns it should work.

exxos wrote: 23 Oct 2025 04:14 If they are genuine 100ns it should work.

:) Now you have me worried. ;) Is fraudulent marking common in EPROMs? I know it is with CPU's etc, but I would have thought EPROMs are cheap enough that even the Chinese would not bother forging them.

abraXXious wrote: 23 Oct 2025 08:27

exxos wrote: 23 Oct 2025 04:14 If they are genuine 100ns it should work.

:) Now you have me worried. ;) Is fraudulent marking common in EPROMs? I know it is with CPU's etc, but I would have thought EPROMs are cheap enough that even the Chinese would not bother forging them.

Almost any IC can be marked as something else so it's not a case of something being cheap enough they wouldn't bother, it's a case of risk vs reward. If they can make a profit then they will do it.

I've had cheap 8 pin op amps from a trusted supplier on eBay that were re-marked and didn't work and they are cheaper than eproms.

Whilst the issue of fake ICs is out there, you just have to accept the risk.

I've had something like 80 RAM ICs from AliExpress and aside from some dead ones they were all genuine, so it's pot luck I'm afraid.

rubber_jonnie wrote: 23 Oct 2025 09:03

abraXXious wrote: 23 Oct 2025 08:27

:) Now you have me worried. ;) Is fraudulent marking common in EPROMs? I know it is with CPU's etc, but I would have thought EPROMs are cheap enough that even the Chinese would not bother forging them.

Almost any IC can be marked as something else so it's not a case of something being cheap enough they wouldn't bother, it's a case of risk vs reward. If they can make a profit then they will do it.

I've had cheap 8 pin op amps from a trusted supplier on eBay that were re-marked and didn't work and they were cheaper than

I guess I was assuming that the actual cost of resurfacing then re-stenciling chips would negate the benefit of selling such a cheap item under false pretenses, obviously labour is even cheaper than I assumed in China to make it financially viable to do this to such low value items.

I might get out the ole' TL866 and see if it has a function to test EPROM read speed.

Given that they even remark TTL chips (pointlessly), which cost pennies, there's no cost point where they don't do it.

It's silly really as it costs them both money and reputation. Far better to have genuinely marked reclaimed chips which have been cleaned and gone through a QA test, which would still be cheaper than remarking, and gain a good reputation and hence more return purchasing.

stephen_usher wrote: 23 Oct 2025 09:17 Given that they even remark TTL chips (pointlessly), which cost pennies, there's no cost point where they don't do it.

It's silly really as it costs them both money and reputation. Far better to have genuinely marked reclaimed chips which have been cleaned and gone through a QA test, which would still be cheaper than remarking, and gain a good reputation and hence more return purchasing.

Exactly what I was thinking. I can understand the theory of ripping consumers off for a quick buck by rebranding low cost chips as significantly more desirable higher cost chips... but it seems pretty stupid and short sighted to ruin your commercial reputation over pennies.

Still, Chinese is Chinese. :)

If you come from China they are most likely reprinted, changed speed grade as minimum.

I suspect all the EPROMS I have purchased over the past few years they are supposed to be SGS brand, but I think they are reprinted TI parts.. The print doesn't look like it used to and the arrays window was generally a lot smaller on the TI parts. But I never conclusively looked into it all.

Expensive parts like the 060 CPUs they reprint the lot. Even genuine rev 6 chips they reprint as rev 6!

Cheaper parts like GALs I had 100 a few years ago, it was like they was all dummy ICs.. No resistance between any pins whatsoever and the chip identifier couldn't detect anything either.. A lot of GALs are reprinted as -7 when they could be anything. I wrote loads about that when I was developing the STE booster.

Like I've been saying lately, China prices are getting more expensive than they are used parts and a lot of them are faulty or not as they appear to be.. By the time you pay shipping and tax.. There's not much price difference in just buying genuine parts from my legitimate brokers.

abraXXious wrote: 23 Oct 2025 09:10
I guess I was assuming that the actual cost of resurfacing then re-stenciling chips would negate the benefit of selling such a cheap item under false pretenses, obviously labour is even cheaper than I assumed in China to make it financially viable to do this to such low value items.

Well if you consider the resurfacing an re-stencilling could be done by laser super quick and automatically, the labour costs are minimal and with lots of people buying IC's for retro hobbies, it's probably worth it if they can shift parts in bulk.

I mean I agree, it seems unsustainable financially, but still it goes on.

As for reputation, I don't think they care as they vanish and appear under another name, or offload stock as fast as possible and let others take the reputational risk.