I’d like to program all those old PROM chips.

I’ve noticed that those chips have a high failure rate

  • on my pdp11/44-CPU an 82S101 was failing
  • for 11/44, I had to program BOOTloader PROMs, a little 512 x 4 bipolar PROM
  • in an RLV12 QBUs RL02 controller, I have a dead 82S181 1K x 8 bipolar PROM.
  • in C64, a dead 82S100 is main reason for system failure,.

 But this project began as an endless story of disappointment and failures.


 I bought an old ALL-07 Hilo programmer on eBay. I choose this model, because

  • it's an universal programmer from 1995, so it has rich support for all those old chips (but it cannot deal with modern chips, of course)
  • my company has also an ALL-07, so in case if trouble I could test & verify by changing parts of both programmes.

Despite it was made in 1995, there is still some support for the ALL-07.

But things went all wrong.

Reworking an ALL-07

The eBay deal was one of the worst I ever made. The programmer was announced as “100% OK”. When it arrived I noticed, that it was not a standalone device with LPT parallel port interface, as I expected. It was another model: no own power supply, and it needed an special ISA interface card to provide LPT signals and power. The dealer knew nothing of this card. He said he had taken the programmer from the hobby workshop of a guy who did not pay him some money back.

I openend the ALL-07, rewired the LPT-interface so I could connect to a normal LPT port, then I bought a little switching power supply and connected it to the ALL-07.

ALL-07 software on virtual PC

The ancient ALL-07 software is DOS only, so I had to setup a virtual machine with Microsoft Virtual PC, where I installed the old control software. I hoped that the parallel port emulation was good enough to let the software control the programmer. All this took two weeks. I switched everything on, and the software made contact to programmer, but said there was "no PAK inserted". a A PAK is an adapter for the programmer base device, so it can program a certain type of chips.

Comparing two ALL-07

I had so much home-build components in my setup now, it was difficult to debug. But I could use the ALL-07 from my company, and this device worked fine on the virtual machine. I took the PAK of my company's ALL-07, plugged it into my own ALL-07, and the software could make contact! So all my workarounds (virtual machine installation, power supply, own LPT adapter) seemed to be OK.

I opened the defective PAK and saw that somebody made heavy repair attempts: a lot of chips where solder out and remounted on sockets. So this PAC definitive had a problem!

Fighting a liar

I was quite angry on the seller, because clearly he was lying to me: He insisted to “have the programmer tested”, but how could he? He didn’t even know that the device needed a special interface card to get powered on. I got rather unfriendly to him, and he bitched back at me. I wanted my money back, he offered my to give me just 50€. I should have taken that money, but I was to upset.

As a result, I got no money at all, and he wrote me a bad eBay feedback: “because I did not payed” ... what an asshole! I was clearly defeated by him.

HILO's still alive

Meanwhile I could made contact to HI-LO Netherlands. They still have old PAKs as spare parts to offer. My 40pin unviersal PAK did cost 25€ + 15€ shipment, so I bought this and tried to forget all the trouble.


Well, at least I tought after all that trouble I had a working programmer now.

I could program an 82S131 Boot PROM for my PDP-11/44. Quite strange, the bit patterns were also copied to the upper half of this ROM, which should have left untouched.

I could program standard 64Kbtye EPROMS (27C512). I failed to program an old 27C16, and I could not program a older EEPROM. Hmm.

To exclude failures in my virtual machine setup, I installed the programmer software also to an old slow notebook (500MHz CPU), but nothing changed.

To program 82S100, I needed an special adapter: ALP.PLS100. I bougth it from HILO Netherlands, for 150€ (they had to produce one for me).

Buying old PROMs

It arrived just before Xmas holidays 2009. I tought I had two boards in my inventory with defective 82S100, so I tried to buy some 82S100. This was not easy. Lot of dealers for obosolete or discontinued chips state they could provide them. But after I sent out a bunch of price request, feedback was poor. Most companies did not answer, some answered “sorry, not available”, one offered me 10 82S100 for 1000€ total (no joke!). Finally I could get 5 chips for total 140€ ... a lot of money. But my zodiac sign is Aries, I hate to give up in the middle.

When the chips arrived, I began to play with my programmer. First surprise: one board did not needed an 82S101 at all, it needed an 82S181!!! My documentation were some bad scans, and I had mistaken the numbers. So it seemed I did not needed so much of these pricvy 82s100 chips ... a mispurchase.

Well, I did not have 82S181, but I could try to read a good 82S181. Next surprise: the ALL-07 had it in his library, but reading delivered always a buffer of hex FF’s, no real content.

I could not get 82S181, but I bought two AMD 27S191 (which have double capicty, and one more address pin).

So after all this strangeness with my ALL-07, there was another chip it could not handle! Maybe not just the PAK, but also the main device is defective.

Trying the 3rd ALL-07

I throw everything into a dark closet and tried to forget the whole project ... and suceeded. A few months later I got an e-mail from an mikrocontroller.net forum member. He had read some old request of me for HILO addresses ... and asked, wether I could need his ALL-07.

Honestly, I was not amused. A bad joke? Start this agony again? But it was an offer I could not refuse.

And this ALL-07 was in pretty good shape: I could program 82S171 and 82S181, and read a 82S100 with it!