SIMM 4 MByte + 1 Mbit parity \ VOGONS

SIMM 4 MByte + 1 Mbit parity

Topic actions

First post, by Grzyb

Posted on 2021-05-04, 16:31

Grzyb Offline

Rank l33t

Rank: l33t
Posts: 2731
Joined: 2019-05-08, 13:47
Location: N53 E15

First, let's have a look at this memory module:

The attachment simm1.jpg is no longer available

4217400 = 4M x 4
two such chips = 4 MByte

HM514100 = 4M x 1
so it's 4 Mbit parity

In general, a perfectly normal SIMM of 4 MB with parity.

But suddenly, I've encountered this one:

The attachment simm2.jpg is no longer available

KM44C4100 = 4M x 4
two such chips = 4 MByte

HYB511000 = 1M x 1
so it would be only 1 Mbit parity

Does it make any sense?
Am I missing something?
Are such modules supposed to work with typical boards?

In 2003, I voted in favour of joining the European Union. However, due to recent developments - especially the restrictions on cash usage - I'm hereby withdrawing my support. DOWN WITH THE EU!

Reply 1 of 1, by Tiido

Posted on 2021-05-04, 16:35

Tiido Offline

Rank l33t

Rank: l33t
Posts: 3608
Joined: 2018-01-14, 04:40
Location: Norway (used to be Estonia)

That doesn't make sense, there's only one parity bit for every 4 addresses... I expect those sticks will not work with a normal board that expects every address to have a parity bit.

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜

Go to top of page Go to top of page

Back to General Old Hardware