VDU, V9958

[BigEd]

Is that like a 64-pin SODIP breakout??

[Aslak3]

Yup. It is my Shrink DIP64 adapter. It spans two breadboard slabs.

As to whether you can buy a ready made one... Probably, but it would cost a fortune.

Where do you live legacy? I could possibly make you one, for the cost of parts - a few pounds at most. If you want a SDIP socket attached, I should have a (recycled) one of those available as well. Let me know.

[legacy]

oh, really thanks, it helps me a lot with the breadboard =D
i live in italy

the guy on ebay should has sold me a V9958 chip with the SDIP socket
not sure about this, the item will arrive in weeks (shipped from china)

[legacy]

about where-to-buy, in this topic (MSX forum) i got a lot of useful information about where-to-buy =)

[legacy]

is there any package PDIP64 of pinch 1.778mm for eagle/CAD ?

[MichaelM]

0.070 inches.

[legacy]

i have redesigned the VDU V9958 (and its package 1.778mm) as Eagle/CAD library's item

[digidice]

legacy wrote:

i have redesigned the VDU V9958 (and its package 1.778mm) as Eagle/CAD library's item

Should post that in a link so that everyone doesnt have to redesign that part for their library.

[Megatron]

Spotted a V9958 Video board here :

http://www.primrosebank.net/computers/m ... _specs.htm


I also spotted a DIP64 adaptor for breadboarding a V9958 IC

http://www.primrosebank.net/computers/m ... design.htm

I believe he still may have some of the adaptors left.

[stevendt]

Hi Folks,

The quoted site is mine

And yes, I do have a few adapters left if anyone is interested. They are the second version of the board, about 1/2" narrower than the photos shown of the V1 board on the webpage

Regards
Dave

Megatron wrote:

Spotted a V9958 Video board here :

http://www.primrosebank.net/computers/m ... _specs.htm


I also spotted a DIP64 adaptor for breadboarding a V9958 IC

http://www.primrosebank.net/computers/m ... design.htm

I believe he still may have some of the adaptors left.

[Martin_H]

Does anyone know if it is possible to use two D41464 DRAM's with a TMS9918a rather than 16 4116 (16k x 1)? Besides reducing the part count significantly, I would avoid the 4116's need for negative and 12 volt power.

The reason I am considering using a TMS 9918a over 9958 is that I can avoid the issues with 0.7 " spacing, and I've found much more information on the TMS9918a.

[Martin_H]

Martin_H wrote:

Does anyone know if it is possible to use two D41464 DRAM's with a TMS9918a rather than 16 4116 (16k x 1)? Besides reducing the part count significantly, I would avoid the 4116's need for negative and 12 volt power.

Some further research let me answer my own question. I read through the data sheets of the 41464 and 4116 DRAMs. The four bit wide chips multiplex their pins for input and output, while the one bit wide chip has separate input and output. I found an article which says that this approach won't work. If you want to avoid the 12v and -5v requirement the way to do it are eight 64kbx1 DRAM's which are 5v only parts. At that point the use of latches with static RAM is probably the best approach.