🚀 go-pugleaf

On 2018-03-30, Andreas Kohlbach <a...@spamfence.net> wrote:

> On 29 Mar 2018 23:10:26 GMT, Charlie Gibbs wrote:
>
>> On 2018-03-29, Andreas Kohlbach <a...@spamfence.net> wrote:
>>
>>> The YouTube channel of the University of Nottingham, better known
>>> as Computerphile, has published a short video about the IMSAI 8080
>>> (next to the Altair in an earlier video)
>>> <https://www.youtube.com/watch?v=trf2Nb1mXIc> where they also
>>> mention that Matthew Broderick showed up with it in the 1983 movie
>>> War Games. Nothing new, but I enjoyed watching it. As all videos
>>> they come up with. :-)
>>
>> I wanted one of those 9600-bps acoustic couplers.  :-)
>>
>> I tried getting my IMSAI going last summer; the processor seemed to
>> act OK, but I suspect the boot ROM has decayed.
>
> Boot rom? Pah! You key in your boot loader on the front panel switches. ;-)

I wish I could.  Unfortunately, depositing bytes into memory from the
front panel switches required a hardware hack that was only present
on the original RAM-4A boards.  I replaced them with a single board
that held 64K and ran _much_ cooler.

>> It appears to be almost impossible to find either a 2708 or a
>> programmer for it, but I've come across a hack that lets you use half
>> of a 2716 instead.  I think I can find a listing of the ROM contents,
>> so there's a chance I could get it going - along with my H19 terminal
>> and the model 35RO Teletype I used as a printer - in my copious free
>> time (hah!).
>
> Of course you could download a boot rom image, burn it to an eprom
> and go from there.

That's what I said - I have to even do a hack to burn an EPROM.
As for the boot ROM image, it's probably printed out on a
moldering piece of teletype paper somewhere in my files.

> But I never had an Altair or IMSAI. Only learned about their
> existence a few years ago when diving into the history on
> vintage (home) computers. Must have been an exciting time
> I totally missed. For once I was way too you and also lived
> in the "wrong country". Suppose you had to live in the US to
> even become aware of them back in the day.

It was a fun time.  Not sure whether I'd do it over again, but
it would be kind of neat to get the IMSAI running again and
driving that Teletype.  If I was really daring (and had tons
of time), I'd try to get those UNISERVO VI-C tape drives
working again.  A friend once hacked together an S-100
interface and managed to read a block of data from them
into his IMSAI.

-- 
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