piclist 2017\09\26\020708a >
Thread: Lost Souls
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face picon face BY : RussellMc email (remove spam text)


On 26 September 2017 at 13:28, mike brown <KILLspammikeTakeThisOuTspamEraseMEn5qmg.com> wrote:

> I still have a Cosmac Elf II that I built around 1977.  It should still
> work, but needs to be tested to verify.  256 bytes of SRAM.  Code is hand
> assembled into hex got easy entry via the hex keypad.  Much more luxurious
> than the previous model since that required you to enter actual binary via
> toggle switches.


​Probably 5101 low power CMOS memory.
(256 x 4 from memory).

If loaded regularly with the same code these started to "remember" their
prior contents when powered off overnight and then restarted.
This could not be relied on as "ROM: but seemed to become more ROM like
with time.
- This was discovered by some students who had a system that ran the same
code which was rekeyed in each day. (Why it was not just left on I know
not).

Russell
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