ACI assembly

softwarejanitor wrote:

Speaking about BiPolar PROMs, does anyone know what programmers can handle them?  Anything recent (USB based, supported by anything close to current OSes/platforms)?  All the ones I remember from back in the day either were standalone, used proprietary interfaces or were parallel port or RS-232 based and required software that was intended for old 8 or 16 bit micros.  I know ther

This thread may be of interest https://www.applefritter.com/content/mmi-6301-prom-burning

The Conitec Galep-5 and the Batronix BX48-II both support some bipolar PROMs and connect via USB.

Note that there never was any standard algorithm for programming bipolar PROMs; the programmer requires explicit support for the vendor and model of device.

Bipolar PROMs are much faster than EPROMs and many of their uses cannot be substituted. Sometimes GALs can be used in place of PROMs.

Such an adapter has already been invented, but it does not fit into the ACI card. You have to modify the board. Here is a link to the project - https://p-l4b.github.io/prom/

I write PROM's on KP556PT11 on a Russian STERCH 007 programmer, USB, Windows 7.

IMG_20220809_103848.jpg

So many questions at once! I see you've already found answers to half of them.

KP556PT11 is a full analogue of 6301, when I was a seller on eBay I sold about 50 such kits (A1, A2, A3, A4) for $20 to over two dozen countries. One guy even put them on the original board, there was one missing, saw a photo of his auction later. Of course they are much cheaper than the 6301, I could meet any demand for them, but in March I was sent away from eBay until January 2031 like the rest of the Russians.

About your adapter, you make it kind of complicated, in my opinion. At the link I gave you above there is a project in EasyEDA format, I would just make some changes there and that's it. It would be better to edit not this project but ACI board for 27c64, it's too complicated because the board is different... Maybe I'll do it myself later. The capacitor is correct, 0,1uF.

You can buy the programmer at Chip and Dip, here's the link  - https://www.chipdip.ru/product/sterh-st-007

Seems here is some pain out there sourcing programmed PROMs for the improved ACI. Hmm. I always wonder why people don't ask the source (me).

I use a Data I/O System 19 programmer (I have two, both worked at the beginning of my Apple-1 mission, now one has an issue, the base system, not the Unipak). These old programmers can be repaired and re-calibrated indefinitely has they do not any proprietary parts such as PLDs, GALs, FPGAs, hybrids. Beginning with the Unisite, Data I/O started to use hybrid pin drivers and these can't be repaired. So stay away from those. This applies to ALL programmers with hybrid pin drivers. This is why I can't recommend the otherwise excellent BP Microsystems BP1200 for which both a DOS based driver and a Windows XP based driver exist. BP Microsystems is still around and they have a very good technical support, but they don't support these old programmers anymore. The drivers are gone on their website BUT if you know the file names you can find them with the Wayback Machine.

I would be wary about trying to program bipolar PROMs with any more modern programmer.  There is a risk that their pin drivers and power supplies are too weak to do the job right. And then you may get lots of rejects (= losing money on wasted blanks) or, worse, fuse regrow. I know this first hand because back in the 1980s I was involved in a programming center.

We learned the lessons with bipolar PROMs and bipolar PALs and used the older Data I/O machines like the System 29 for them. The BP 1200 also did that job well but IIRC there were slightly more rejects with it, compared to the Data I/O 29. But nothing dramatic. I know for sure it's the difference in the programmers because we split huge lots which had to be programmed over night and all programmers produced the same final IC, with the same code, the same test vectors, and the same lot(s) of blanks. This experience with millions of PROMs and PLDs programmed over the many years made me wary about modern programmers as far as fuse link ICs have to be programmed. For all EEPROM based programmable logic, any professional grade programmer works fine. The lower end probably being the Galep 3, but it can't do test vectors to excercise the PLDs after programming.

Replacing PROMs with 2716 EPROMs is not smart unless you have lots of them. These are getting quite rare. The 2732 is a better choice and easier to find.

Timing wise the EPROMs are less critical than the PROMs. The Apple-1 has a quirk that the bus timing does not use the PHI1, PHI2 clocks generated by the 6502. The PHI1, PHI2 on the Apple-1 bus are fake and the fake PHI2 on the bus may fall too soon compared to the 6502's honest PHI2. A slow EPROM won't stop driving the bus too soon, but a fast PROM might, and then the 6502 may grab data from the data bus which is just there because of parasitic capacitance. Good luck with that. It's hanging on a thin thread.

For a typical hobbyist, buying a PROM programmer just to be able to make a few PROMs is not smart, but a colossal waste of time and money. Same thing with building your own PROM programmer. If you do it properly, and have beefy pin drivers and power supplies and the correct rise and fall times (very important !), following the PROM manufacturer's programming specs, such a home built programmer may deliver the same reliable programming as a professional programmer from Data I/O or BP Microsystems. But it will take you many, many hours to build one and to test the software, and you will waste a lot of blanks before everything works. (Don't ask me how I know that ;-)

There were other programmers like Stag or System General but you can't get the service manuals for them, and the System General TURPRO needs a dongle with is almost never sold with the programmer when it appears on Ebay.  Without the dongle you can only read out parts and program a few. For the other parts you had to pay, Hence, the dongle. Suckers. I would not buy a programmer from them anymore.

Rule #1 when buying IC programmers: get all the manuals, device support lists, service manuals, schematics, and driver software (if needed) BEFORE you commit to buy the programmer. Otherwise you buy a boat anchor.

And stay way from Intersil bipilar PROMs and MMI PROMs/PALs from the years 1976 to 1979. Intersil PROMs never worked right (their understanding of the AIM process was lacking, despite they got nice patents on their "fuse") and  MMI were unable to make thin films with the proper sheet rho to get good yield. This problem nearly killed the otherwise great PAL (and MMI as such). It was later rectified, of course.

There are still lots and lots of bipolar PROMs available at IC brokers but avoid the Chinese sources: the PROMs from China often are "refurbished" which means programmed, and so they are worthless. You have to buy PROMs from a reputable IC broker who can guarantee that they are blank.

So far my 10 cents on PROMs and PROM programmers. If you need a set of ACI PROMs, send me a PM.

- Uncle Bernie

Hi!

I think your plan looks good. But... You need to look at the access time of the 2716 you are going to use. The original bipolar PROMS are quite fast (< 50 ns). Some 2716 are not fast enough. Here is my analysis: The ACI board delivers chip select to the ROM socket one LS gate delay (~30 ns) after the rising edge of ø2. The 6502 needs the data 100 ns before the falling edge of ø2. The duration of ø2 is 560 ns.  Therefore the required access time is  560 - 30 - 100 = 430 ns.

Some 2716 are 450 ns which won't quite make it. You need to pick a 2716 or 27C16 that is 350 ns or 250 ns.

Note: I came up with this before Uncle Bernie mentioned that the Apple-1 uses a 'fake' ø2 signal. I need to learn what this means and understand how it affects my math.

Jeff.

P.S. Don't forget to tie 2716 Vpp to +5 (pin 21) 

In post# 21, jmmh wrote:

"I need to learn what this means and understand how it affects my math."

Uncle Bernie answers:

Alas, this is not easy. The fake PHI2 comes earlier than the "real" PHI2 so generously offered by the 6502 itself. This is the very same PHI2 it 6502 uses internally for all circuits. Same rule for the PHI1 it makes. This is the real deal coming out of the 6502's internal non-overlap clock driver. I know for certain as I have the transistor level schematic of the 6502.

The delay between the PHI0 input and the PHI1,  PHI2 outputs made by the 6502 is real and buys you some additional time for the access to the EPROM on the ACI where the "fake" PHI2 is used. But this is highly elusive. The numbers in the datasheet show the extremes but where will your 6502 be ? An oscilloscope of sufficient performance can tell. But then you have the numbers for your specimen. This is not the way to design robust circuits.

But when we get sloppy we could postulate that any 2716 and 2732 will be fast enough if you tie the /CS signal from the PROM sockets to the /OE of these EPROMs. And ground their /CS permanently. This means they they will look for the contents in their belly just after the addresses stabilize (in PHI1, much earlier then PHI2) and the data will be ready to be driven to the bus when /OE is activated. This activates only the bus drivers of the EPROM and is much faster than getting the EPROM selected with /CS.

The above is valid for unmodified ACIs only. All my modified (Gen1 and Gen2 improved) ACI synchronize the comparator output to PHI2 using half of the 74LS74 which is unused in the original circuit. This improves reliability by avoiding changing PROM addresses during PHI2. Which would lead to weird values being read out from the PROM at times. I found it happens rarely with the LM311 but the 741 opamp based comparator circuit would never yield a working ACI without the added synchronizer flipflop. Alas, this synchronizer flipflop steals some access time budget. No issue with real PROMs, though, as they are fast enough. And anyone having a Gen1 or Gen2 improved ACI PCB from me should also have real PROMs. So this is a non-issue from my point of view. But a trap for those would want to build Frankenstein ACIs.

- Uncle Bernie

"I can't read that link at all, since I don't know Russian.  No idea what that price translates into Dollars.  And I'm not sure I'd be able to order due to all the sanctions like you can't sell on eBay."

No problem, I can translate it for you. The programmer supports more than a thousand microchips in DIP 8 to DIP 42 packages, such as EPROM, EEPROM, serial EEPROM, FLASH, microcontrollers, PLM, PAL, EPLD etc. Works with DOS, Windows 95/98/ME, NT/2000/XP/Vista/7 and as the guy I bought it from said, Windows 10 if you dance with tambourine a bit, but I have not tried it.

As for the price, I bought it from a guy for $200, new at the time it cost about $350. Price in rubles has not changed, but with the introduction of all these sanctions demand for $ dropped dramatically, and along with it the rate. There is nowhere to spend it, the payments with China and Belarus are made in rubles, and Russian bank cards are not accepted anywhere else...  So now it's about $550, which, as I understand it, is a bit expensive for you.

Can I give you one piece of advice? You can install Windows on your Mac through the MacOS built-in Bootcamp utility. When you turn on your computer, hold down alt and you're taken to a menu to select a bootable volume. You can also use Windows on your Mac using Paralells Desktop. It's not a problem at all.