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Naibo
Reged: 10/17/07
Posts: 131
Loc: Tianjin China
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Re: DU: Saturday morning bits (updated)
01/07/18 07:00 AM Attachment: vjs.png 96 KB (0 downloads)


Made a working stepping stage driver, and then tried the new dumped vj with it. Yes, vj uses the similar hardware -- two 68000 based boards, and a Windows PC as a slave device (contains 3x mpeg1 decorders, at least for stepping stage).

However, in mame's tile viewer, vertical stripes are shown from the two 16-bit 4-MegaByte rom chips (mr98053-03.ic14 and mr98053-04.ic36). Checked using hex editor, all even bytes are filled with 0xff in their front half part. Maybe these 2 rom chips use non-standard pin configuration of address/-cs/-oe lines?

In addition to the dumped GAL and CPLD, there is another GAL chip(IC 57), which hasn't a sticker, close to the 68000 CPU and the already dumped GAL. Dump it may help understand the address decoding.

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Entire thread
Subject Posted by Posted on
* DU: Saturday morning bits (updated) SmitdoggAdministrator 12/30/17 07:48 PM
. * Re: DU: Saturday morning bits (updated) Naibo  01/07/18 07:00 AM
. * Re: DU: Saturday morning bits (updated) SmitdoggAdministrator  01/07/18 07:10 AM
. * Re: DU: Saturday morning bits (updated) Haze  01/07/18 01:40 PM
. * Re: DU: Saturday morning bits (updated) Naibo  01/08/18 09:42 AM
. * Re: DU: Saturday morning bits (updated) SmitdoggAdministrator  01/08/18 06:53 PM
. * Re: DU: Saturday morning bits (updated) gregf  12/30/17 11:43 PM
. * Re: DU: Saturday morning bits (updated) SmitdoggAdministrator  12/30/17 11:51 PM
. * Re: DU: Saturday morning bits gregf  12/31/17 12:19 AM
. * Re: DU: Saturday morning bits (updated) Haze  12/31/17 12:18 AM
. * Re: DU: Saturday morning bits (updated) SmitdoggAdministrator  12/31/17 12:19 AM
. * Re: DU: Saturday morning bits (updated) Haze  12/31/17 12:22 AM
. * Re: DU: Saturday morning bits (updated) Haze  12/31/17 12:30 AM
. * Re: DU: Saturday morning bits (updated) Naibo  12/30/17 11:21 PM
. * Re: DU: Saturday morning bits (updated) SmitdoggAdministrator  12/30/17 11:23 PM
. * Re: DU: Saturday morning bits SmitdoggAdministrator  12/30/17 10:02 PM
. * Re: DU: Saturday morning bits agard  12/30/17 10:01 PM
. * Re: DU: Saturday morning bits Nate  01/07/18 07:34 PM

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