1. VintHPcom@groups.io
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Mystery roms for the 9830? #VintageHPComputers

Lee A. White
 

I have uploaded the contents of two 2708 Eproms from my days as an engineer at HP working on the 9830 and other 98x0 calculators and peripherals, (and later - on the 9845). These roms should be for the 9830 and they may be the "in house" roms that contained all the software used by engineering to develop the software for the 9830 calculator. It is likely that is what they are and if so, they would be of extreme value. That software was super secret - very few had access.They may also be some other Roms for option cards or software extensions - still of some interest. The roms are dated 9 June of 1976. Given their age, the data may be junk too. So, anyone up to the challenge of figuring out what they are?

Also, give credit to and thanks to Arnie Berger for building a circuit, dumping them to a logic analyzer, and then transferring them to a readable flle.

Thanks Arnie.

Lee W
Achim Buerger
 

Hi Lee,

very interesting. I could try to load the ROMs in my GO9800 emulator. With the build-in disassembler I could try to figure out the functionality.

After a quick peek into the data, I can not create anything usefull. I took the data0 to data 7 bit values and assembled them in low to high and also high to low order. Then I combined the values of both EPROMs to 16 bit words in several ways but could not get any values which could be 9800 binary code. To me it looks like junk data.
There are hints, that the data maybe either corrupted or not 9800 binary code:
1. The data0 and data7 bits are mostly constant 0 (zero) in both ERPOM dumps. This cannot be true for 9800 binary code.
2. the first 19 values in Dump-1 are completely missing

Maybe the bit values have to be reordered in another way or inverted or whatever. Without any hint its quite difficult to find out.

Achim
Arnie Berger
 

I tried to decode some 2708 EPROMS for Lee White. I created a 10-bit counter in a PLD and used it as the address generator. I hooked my trusty logic analyzer to the address and data lines and read the ROMs. The data did not appear to be anything real in either ROM. One data bit was stuck on one of the ROMs. The ROMs were dated 1976.

 

My suspicion is that the stored charge on the MOSFET gates just eventually leak off. I think if anyone can dig up data on the expected lifetime of an EPROM from this era you’d find something in the neighborhood of 10 years.

 

I suspect that once the one-voltage 2716s came out and those coming after that, probably had better data retention numbers.

 

Arnie

 

 

 

From: VintHPcom@groups.io <VintHPcom@groups.io> On Behalf Of thermoman via Groups.Io
Sent: Wednesday, October 2, 2019 6:21 PM
To: VintHPcom@groups.io
Subject: [VintHPcom] Mystery roms for the 9830? #VintageHPComputers

 

I have uploaded the contents of two 2708 Eproms from my days as an engineer at HP working on the 9830 and other 98x0 calculators and peripherals, (and later - on the 9845). These roms should be for the 9830 and they may be the "in house" roms that contained all the software used by engineering to develop the software for the 9830 calculator. It is likely that is what they are and if so, they would be of extreme value. That software was super secret - very few had access.They may also be some other Roms for option cards or software extensions - still of some interest. The roms are dated 9 June of 1976. Given their age, the data may be junk too. So, anyone up to the challenge of figuring out what they are?

Also, give credit to and thanks to Arnie Berger for building a circuit, dumping them to a logic analyzer, and then transferring them to a readable flle.

Thanks Arnie.

Lee W

Lee A. White
 

Thanks again to Arnie for a job well done, and at a time when he was pretty busy with other responsibilities too.
 
I am certain that these Eproms did originally contain 9830 binary code, and that the code in them was most probably the collection of software development tools used to produce the 9830 operating system and optin rom code. Much less likely, they cold be loaded with some code for an add on rom - probably for a peripheral interface - like HPIB as an example. I can not think of anything else I would have had an Eprom for at that time. I suppose there is some slight possibility that some of it is HP Basic source code, but that is very unlikely in my estimation.
 
I was not a software development engineer and my 45 year old memories are a bit foggy to say the least, but again as I recall these roms were to be installed on a PCB in an option rom module to be inserted in one of the option rom slots in the left hand side of the case of the 9830. Also as I recall, the "in house" software development tools could not be loaded from tape. It is possible the only reason for that was security - no tapes means no quick and easy duplication and better control of access to that software. Remember, HP's lucrative software market was under attack by that little company on the west coast.
 
LeeW
Achim Buerger
 

For comparison I uploaded a dump of the complete HP9830A main memory (ROM+RAM), generated at runtime with a self-programmed PEEK binary.
https://groups.io/g/VintHPcom/files/HP9830A%20Memory%20Dump
I don't remember which plug-in ROMs where present at that time.
The second file is the disassembled dump. All values are in octal code.
There are typical, easy to identify values, which have to appear in a binary program, such as the code 170402 for RET. If this doesn't occur, it's propably no machine code.

Achim
Lee A. White
 

Points well made.
 
I remember that I did have an Eprom programmer that worked with the 2708 chips and that I did read out some chips back in about 1982. The programmer was attached to the parallel port of a very early IBM PC and the data was stored on a 5 inch single sided single density floppy. As I recall, it was saved in a comma delimited text file. I may still have that floppy, but it may not be readable either. I will look for it next month when I am at my other house where it is.
 
I have an old PC there and should have an old 5 inch drive as well - just have to put it all together and bring it up. If I do find the disk and can get the PC up and running, are there any special procedures I should follow to re-condition the floppy before I try to read it?
 
If all that works, it will be interested to see what differences there are between the old and the new dumps.
 
Lee 

Sent: Thursday, October 03, 2019 1:56 PM
Subject: Re: [VintHPcom] Mystery roms for the 9830? #VintageHPComputers

For comparison I uploaded a dump of the complete HP9830A main memory (ROM+RAM), generated at runtime with a self-programmed PEEK binary.
https://groups.io/g/VintHPcom/files/HP9830A%20Memory%20Dump
I don't remember which plug-in ROMs where present at that time.
The second file is the disassembled dump. All values are in octal code.
There are typical, easy to identify values, which have to appear in a binary program, such as the code 170402 for RET. If this doesn't occur, it's propably no machine code.

Achim

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