Maker Pro
Maker Pro

Multiple EPROMs in one large switchable-bank EPROM?

TTL

Oct 24, 2013
187
Joined
Oct 24, 2013
Messages
187
Some drum machine voice boards contain two 2764 EPROMs which can be configured for multiple sounds, longer sounds and so on:
Screen Shot 2019-09-17 at 21.06.47.png
Screen Shot 2019-09-17 at 21.06.16.png


If the voice board is configured for two EPROMs and each socket (U8, U9) is populated with a multi-bank EPROM adapter... could I switch banks of both boards at once simply by joining the 4 MSQ signals together to one DIP switch, like this?

dip-control.png
 

Harald Kapp

Moderator
Moderator
Nov 17, 2011
12,720
Joined
Nov 17, 2011
Messages
12,720
Of course. What makes you think this wouldn't be possible?
 

TTL

Oct 24, 2013
187
Joined
Oct 24, 2013
Messages
187
Just my lack of knowledge, concerned that the 2nd EPROM would be affected by the first one. But I'm learning :)
Thanks again for confirming.
 

Sandrow

Jun 7, 2021
1
Joined
Jun 7, 2021
Messages
1
Hi all there, found this thread and then subscribed instantly to this forum.

I have an E-MU Drumulator which is basically the same concept, a drum machine based on Eprom sound memory banks.

I have some questions for you.

1) About "Stacking" or "Paging" several codes into one eprom:

@Harald Kapp, You wrote:
"Use the three uppermost bits to emulate 2732 memory chips. 8 images of those will fit into one 27256.
This is very likely the same method used in the circuit in your image using a 27512 chip and the 4 uppermost address bits to select one out of 16 images from 2732 chips."

This doesn't sound clear to me.
In other words, what should I actually must do?

2) Will the scheme with pull ups made by @TTL works on this machine?

Some technical informations about Drumulator here below:

Schermata 2021-06-07 alle 14.54.14.png Schermata 2021-06-07 alle 15.12.19.png Schermata 2021-06-07 alle 15.13.20.png

C EPROM.jpg

Thank you very much
Cheers.
S.
 
Last edited:

mahdi93

Jul 1, 2021
1
Joined
Jul 1, 2021
Messages
1
sorry guys for stupid question i'm noob on this but here's my idea :
i have .bin file in 27c256 in my car control unit
i wanna make 4 bin file in that control unit ( ecu )
so i should use 1mb eprom right ? i got a 27SF010 because its flashable and it replace the 27c
the 27c256 in DIP28 and the 27SF010 is DIP32
can somone please show me a simple shematic on how to make it work ?
 
Top