HP 9915A failed 8048

[js at cimmeri.com]

On 2/26/2022 3:21 PM, Tony Duell via 
cctalk wrote:
> On Sat, Feb 26, 2022 at 5:19 PM js--- via cctalk<cctalk at classiccmp.org>  wrote:
>
>> As the chances of success are highly
>> improbable, looks like I'm SOL on this
>> particular motherboard.
> My bench is rather full at the moment and will be for a few more weeks...
>
> But if you get no other help and you can wait a bit, I believe one of
> my old EPROM programmers can read the 8048/8748 with the right
> adaptor, and the schematic of that is in the manual. I also have a
> working (I hope) HP9915. So I could have a go at making said adaptor,
> extracting the 8048 from my HP9915, and readng it out. You would then
> have to find somebody who could program the ROM image into an 8748.
>
> -tony


Hi, Tony!  Long time!

Thank you VERY MUCH for your very 
generous offer!

Dave McGuire was extremely kind to send 
me a ROM dump of the HP 9915's 8048, 
that he had -- to my amazement -- 
already made for himself.  So to my 
complete surprise, I do have the ROM 
contents at this point.

I've a Data I/O 2900 which supposedly 
can program the 8748, so I'll give that 
a try if I can figure out how to use it 
again (been a long time).   I've ordered 
a NOS 8748 off eBay.

I'll give all this a try and post 
results here.

- John Singleton