Elf99 - rebirth of a classic

From: jpero_at_pop.cgocable.net <(jpero_at_pop.cgocable.net)>
Date: Mon Nov 9 13:26:12 1998

> Date: Mon, 9 Nov 1998 18:13:15 -0500 (EST)
> Reply-to: classiccmp_at_u.washington.edu
> From: Ethan Dicks <erd_at_infinet.com>
> To: "Discussion re-collecting of classic computers" <classiccmp_at_u.washington.edu>
> Subject: Re: Elf99 - rebirth of a classic

> I originally wrote:
> > < I have been in discussion with some folks about 1802's and the possibili
> > < of producing a modern PCB for the Popular Electronics Elf design...
> >
> > < How authentic should a modern Elf be? Try to use 1822/2101 RAM or use
>
> Allison Parent resonds:
> > If you're building an elf then 2101, if your doing superElf go for 32k
> > 62256.

Better use widely available SRAMs like you see on motherboard caches
in DIP packages? One 64K x 8bit chip cost $5 at any speeds low as
15ns but it will work in 400ns cycle time machines.

>
> If I can lay my hands on a quantity of 1822/2101 RAMs, then I agree,
> even though they will cost as much as the CPU. The 6264 was a fallback.
> In any case, I would decode 7 or 8 upper address bits if I went with
> a larger SRAM and allow the user to stick in there what they wanted.
> One other suggestion is room for a ROM. I could wire in two or three JEDEC
> sockets and let the builder pick what to go in the, one 62256 or a couple
> of 6264's and a 27128, for example.

Better design the circuit to accept standard memories, ROM's also
preflashed flash chips in place of ROM's as a suggestion.

>
> The problem with replicating the SuperElf is the keyboard. I have no
> idea where to get that chip from (74941?), nor an inexpensive source
> for that many pushbuttons (including some latching ones). I can see
> the keys coming to $2 to $3 each if bought from a standard vendor.

Make a standard keyboard convertors based on PIC ic to spit out ascii
binary using standard AT and PS/2 keyboards? That is far easier than
trying to scrap already valueable stuff for needed parts and
suitable "old" keyboards is hard enough to find already as is.
$10 dollars keyboard and a $20 worth of that little converter kit is
appealing I think.

Snip!

Jason D.
email: jpero_at_cgocable.net
Pero, Jason D.
Received on Mon Nov 09 1998 - 13:26:12 GMT