exxos's Atari, Amiga & retro forum

Given that the *1772 chips were only used over a relatively short period from the mid-80s until the early 90s in "home" computers they probably weren't made in huge quantities to begin with, relative to the chips used in the IBM PC and clones, so it's not surprising that they don't have stock any more.

Other than the Atari ST I can only remember BBC Masters and BBC Model B upgrades using the 1772.

stephen_usher wrote: 15 Sep 2023 12:08 Other than the Atari ST I can only remember BBC Masters and BBC Model B upgrades using the 1772.

I think some of the Sinclair QL floppy add-on cards had them too.

But in terms of manufacturing market that's still tiny.

IIRC many of the BBC B upgrades started with the 1770...as an alternative to the original 8271designed onto the motherboard

A guy who seems to do spectrum repairs bought the remaining of my stock last week. So I don't know if there is some spectrum machines out there which use the chip ?

It is looking like ~£42 is going to be the best price I could do in my store. I would have to buy 135 of them as well :( But this is basically the last chance buy for them now. As they are pushing £100 now. But nobody is going to pay that. I think £42 is a lot. But that is the cheapest they are ever going to be now.

exxos wrote: 15 Sep 2023 13:27 A guy who seems to do spectrum repairs bought the remaining of my stock last week. So I don't know if there is some spectrum machines out there which use the chip ?

Yes almost all 3rd party floppy disk drive controllers for the Spectrum use 1772. But I am surprised many want to buy one considering that DIVide Future is so cheap and good.

Russian Spectrum clones used the KR1818VG93 instead which I think is a clone of a WDC 1793 (or maybe Fujitsu MB8877A)

I never knew until today that we (Toshiba) made the Ajax chip.

I think I have found the earlier WD1772 00-02 chips for a almost reasonable price :) hopefully it is not a scam :hide:

EDIT:

So I should have around 300 of them.. Geese it's going to take forever to pay off my credit card buying these things. The things I do for the community!! :lol: :roll:

The WD1772 was also used in some later Atari 8-bit drives, like the XF-551.

I don't know exactly the reason, but I remember the WD1772 being quite expensive years ago already. It was always more expensive than other WD controllers like the WD279X.

alexh wrote: 15 Sep 2023 14:51 I never knew until today that we (Toshiba) made the Ajax chip.

Interesting, missed this comment earlier. Do you know if the company still has any masks or layout files, or whatever, for the Ajax, or for that matter for any interesting old school chip?

ijor wrote: 21 Sep 2023 04:58 Interesting, missed this comment earlier. Do you know if the company still has any masks or layout files, or whatever, for the Ajax, or for that matter for any interesting old school chip?

Certainly not here in the UK site. We were only acquired by Toshiba in 2014. If we ever have visitors from JPN I'll ask about it.

I imagine it depends how much of the WDC design Toshiba inherited. Toshiba almost certainly had a completely different process to WDC and so couldn't use any of their masks/layout. It was just before logic synthesis took off so the design was probably schematics and re-made?