6 Feb
2015
6 Feb
'15
4:16 p.m.
On 2015-Feb-06, at 3:53 AM, Johnny Billquist wrote:
On 2015-02-06 12:41, Roe Peterson wrote:
Ah, so 2764, not 64K bytes... Oh well... :-)
When did people start counting memory sizes in bits???
Oh, at least as early as the mid-70s, with the 2708 (1KByte).
Yes, I too wish they had used bytes for eprom sizes.
On Feb 6, 2015, at 4:11 AM, Johnny Billquist
<bqt at update.uu.se> wrote:
2716 = 16k bits = 2kbytes X 8 bits
2764 = 64k bits = 8kbytes X 8 bits
The latest rom images for the 11/23+ require 8kbyte chips. On 2015-02-05 19:49, Roe Peterson wrote:
I want to update the EPROMs on my 11/23+, which currently has 2716s. I'm going to
need 64k chips, and I understand 2764s won't work on this board.
What are my replacement options? I have a fairly capable programmer, it can probably
handle anything with 64k capacity.
??? I don't get it.
64K chips? The 11/23 currently uses the 2716, which is what? 2K (bytes)? I doubt there
are any more address lines going to that chip in the first place, and second, the memory
is mapped in the I/O space which have a total of 8K, and that should cover not only the
boot rom, but also all CSRs of all devices you have in the machine. A 64K chip is going to
be totally meaningless.
So why are you looking for a 64K chip? (27512 I would assume that would be...)