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Reading HP67 ROMs
06-29-2022, 02:06 AM (This post was last modified: 06-29-2022 02:07 AM by teenix.)
Post: #21
RE: Reading HP67 ROMs
Hi all,

I was reading the 1818-0229 ROM chip listed as ROM 5 in the 97 service manual to test some code mods because it is accessed from ROM Bank 1 and is now working ok.

I then thought that this was supposed to be the highest ROM with RAM included on chip and then logically this would be the highest RAM bank, address space $30 - $3F, but it only read back from address space $20 - $2F.

The plot thickens.

cheers

Tony
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07-12-2022, 03:28 AM (This post was last modified: 07-12-2022 03:37 AM by teenix.)
Post: #22
RE: Reading HP67 ROMs
Hi all,

I used my ROM reader project to read all the ROMs from a HP-97 including the ROM0 display driver, and then also verify the RAM. I found one chip which the RAM seemed consistently faulty.

I've put these in a data base of sorts which the PC program can use for IC access. These are the IC's it has so far, with model and HEX ROM start addresses.

1818-0267 97 0
1818-0228 97 400
1818-0226 97 800
1818-0233 97 C00
1818-0229 97 10400
1818-0230 97 10800

I'll add more as I can. Any user can add more ROMs by entering the reading requirements like start address etc.

During a ROM read if a comparison file is available, the incoming data will be checked while the read is in progress. If the comparison file is not available, then one can be easily generated after the initial read takes place.

The circuit board needs a few mods, so I will tackle that as time permits and then make the project available.


Just a quick note, I've also been playing around with ROM IC replacements and after fiddling with some code and circuit designs, I think I have a setup that will work and It should fit into the same space as the original 8 pin ROMs. The ROM 0 will need extra work because it also controls the display anodes which I haven't quite figured out yet, so it still needs some work, plus I need to create a test jig to simulate the Sync, Is and Data busses and verify its operation before trying it out for real.

cheers

Tony
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07-14-2022, 11:11 AM
Post: #23
RE: Reading HP67 ROMs
This is great news, Tony! If it's already possible to plug it on Woodstock and Spice calculator ROMs, I can help building the library.

And it will help a lot on finally diagnosing and fixing my dead Hp67 machines!

Eduardo
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07-21-2022, 01:34 AM
Post: #24
RE: Reading HP67 ROMs
Hi all,

I've uploaded the ROM reader project files to the web page...

http://teenix.org/ROMreader.zip

In the zip file is the circuit and PCB design gerber files plus PIC code, a companion Windows program and PDF help file. I have also included ROM files for HP97 and HP67.

cheers

Tony
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07-21-2022, 02:36 AM
Post: #25
RE: Reading HP67 ROMs
Hi,Tony

The link seems failed.

HP35 HP45 HP55 HP65 HP67 HP21 HP25 HP29C HP19C HP97 HP10C HP11C HP12C HP15C HP16C HP31E HP32E HP33E HP33C HP34C HP37E HP38E HP38C HP41
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07-21-2022, 02:58 AM
Post: #26
RE: Reading HP67 ROMs
(07-21-2022 02:36 AM)tangdfx Wrote:  Hi,Tony

The link seems failed.

Apologies, it seems ok now.

cheers

Tony
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07-21-2022, 03:19 AM
Post: #27
RE: Reading HP67 ROMs
Thank you Tony.

It works now.

By the way, is there is rom list that still missing on public domain?

As far as I know, there is HP 10 which is a hybrid CPU chip can not use this rom reader.

And also the famous HP95C. Maybe someone own the HP95C could read out the ROM.

Except these two, are there any more? (The domain is limited in classic ,woodstock, spice)

HP35 HP45 HP55 HP65 HP67 HP21 HP25 HP29C HP19C HP97 HP10C HP11C HP12C HP15C HP16C HP31E HP32E HP33E HP33C HP34C HP37E HP38E HP38C HP41
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07-21-2022, 03:48 AM
Post: #28
RE: Reading HP67 ROMs
(07-21-2022 03:19 AM)tangdfx Wrote:  Thank you Tony.

It works now.

By the way, is there is rom list that still missing on public domain?

As far as I know, there is HP 10 which is a hybrid CPU chip can not use this rom reader.

And also the famous HP95C. Maybe someone own the HP95C could read out the ROM.

Except these two, are there any more? (The domain is limited in classic ,woodstock, spice)

I don't think you'll find the 95C ROM codes as it was never released.

The ROM for the HP10 is embedded in the large IC so can't be read without destruction of the package. I wrote my own version of the code which is in my HP-10 simulator.

cheers

Tony
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07-21-2022, 04:02 AM
Post: #29
RE: Reading HP67 ROMs
Hi, Tony

I know.

But I am sure someone in this forum has an physical HP95C even it has never been released.

Of course the owner may not consider desoldering the ROM chip.

HP35 HP45 HP55 HP65 HP67 HP21 HP25 HP29C HP19C HP97 HP10C HP11C HP12C HP15C HP16C HP31E HP32E HP33E HP33C HP34C HP37E HP38E HP38C HP41
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07-29-2022, 08:38 AM (This post was last modified: 07-29-2022 08:40 AM by teenix.)
Post: #30
RE: Reading HP67 ROMs
Hi all,

I have a design for a ROM replacement now. The circuit board measure 11mm x 8mm and should fit where the original 8 pin ROMs were on the CPU board. I was lucky to find a processor chip to use as there are not many around until it seems sometime mid 2023. I have been working on the code but not fully tested yet. As well as act like a ROM it has to decipher a few instructions and then act on those, mainly for transferring RAM etc. The processor can only execute about 6 instruction at certain times during the PHI clocks so it is a bit of a challenge.

I still have a bit to go because testing will take some time.

cheers

Tony


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07-30-2022, 09:05 AM
Post: #31
RE: Reading HP67 ROMs
Amazing work in these trying times.
It would be amazing work even if the times weren't so trying.


Pauli
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07-30-2022, 10:23 AM
Post: #32
RE: Reading HP67 ROMs
You could use this picture as your avatar:

[Image: attachment.php?aid=10913]
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08-08-2022, 03:39 AM
Post: #33
RE: Reading HP67 ROMs
Perhaps if I get it to work :-)

Just about to power up the bread boarded design. It has a second programmed controller which talks to the PC and also acts a bit like the ACT with Phi1, Phi2 and SYNC output signals, and the bidirectional IS and DATA buses.

cheers

Tony
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