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Re: Forgottenmyname - Progress
Posted: 18 Sep 2018 19:28
by exxos
Forgottenmyname wrote: 18 Sep 2018 19:21
1 step forward is that i have a stable screen, although its yellow and im back to the 2mhz pulses on /AS and the data lines
Did you do this one as well ?
https://www.exxosforum.co.uk/forum/viewt ... 099#p10098
Re: Forgottenmyname - Progress
Posted: 18 Sep 2018 19:32
by PhilC
that'll be a no, lol
Re: Forgottenmyname - Progress
Posted: 18 Sep 2018 19:33
by exxos
C'mon keep up :P
:lolbig:
Re: Forgottenmyname - Progress
Posted: 18 Sep 2018 19:53
by PhilC
I just did, it's not pretty, :lol:
still getting /AS as 2mhz btw
Re: Forgottenmyname - Progress
Posted: 18 Sep 2018 19:58
by exxos
Just to check you did solder the jumper links up ?
Re: Forgottenmyname - Progress
Posted: 18 Sep 2018 20:03
by PhilC
All 5 yes
Re: Forgottenmyname - Progress
Posted: 18 Sep 2018 21:15
by PhilC
Just looking at the schematic for the ROM, on the Mega and ST A16 is also /OE on the ROMS but on the STF A16 is an individual entity. Should this be tied into /OE as well? I'm getting /OE mostly high on the ROM but with a few small blips once in a while. /OE Being high is Read disabled right?
Re: Forgottenmyname - Progress
Posted: 18 Sep 2018 21:27
by exxos
Forgottenmyname wrote: 18 Sep 2018 21:15
Just looking at the schematic for the ROM, on the Mega and ST A16 is also /OE on the ROMS but on the STF A16 is an individual entity. Should this be tied into /OE as well? I'm getting /OE mostly high on the ROM but with a few small blips once in a while. /OE Being high is Read disabled right?
OE HI = ROM disabled.
Its how the ROMs are always wired up on my ROM boards and boosters. I don't use any address lines as chip enable lines, I just tie CE to gnd instead and just just OE.
I will have a look on my STFM rom board just to see how that was wired up..
Re: Forgottenmyname - Progress
Posted: 18 Sep 2018 21:34
by exxos
OK so probably the confusion over A16 is 6 ROM vs 2 ROMs. A16 is wired for "2 roms" but of course thats 2x8 bit roms, whereas I use 1x16bit ROM. So A16 is correct. GLUE decodes the ROM address which drives the OE (on the plcc rom) via the LS11.
So its all correct...
Re: Forgottenmyname - Progress
Posted: 18 Sep 2018 21:42
by PhilC
Ok, so all three ROM1,2,3 inputs have to be high to disable the /OE on the ROM. Can you think of any reason that the GLUE is disabling the ROM?
I don't suppose there's some GLUE logic diagram around anywhere is there?