3 - 16k binaries on an 27C512 Eprom.
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From: Clocky on 3 Aug 2010 09:58 Sam wrote: > I thougth "my" schematic was very clear DMackey828... > It is clear, thanks for putting it up. > To the C64 only connect D0-D7, A0-A13, VCC, GND, VPP and CE. > Pin 1 and 28 are connected to VCC on the C64C so if Pin 1 of a 27512 is inserted into the socket and the A15 grounded with the switch it effectively shorts VCC to ground, that's why Pin 1 of the 27512 must not be inserted into the socket.
From: Sam on 3 Aug 2010 10:50 On 3 aug, 15:58, "Clocky" <notg...(a)happen.com> wrote: > Sam wrote: > > I thougth "my" schematic was very clear DMackey828... > > It is clear, thanks for putting it up. > > > To the C64 only connect D0-D7, A0-A13, VCC, GND, VPP and CE. > > Pin 1 and 28 are connected to VCC on the C64C so if Pin 1 of a 27512 is > inserted into the socket and the A15 grounded with the switch it effectively > shorts VCC to ground, that's why Pin 1 of the 27512 must not be inserted > into the socket. Off course not Clocky.. Only connect the pins I said. Also A14 must not be inserted. Pin 27 is also connected to VCC.. :-) Regards, SAM
From: DMackey828 on 3 Aug 2010 17:34 On Sat, 31 Jul 2010 18:07:58 -0400, DMackey828 <n2dvm(a)NOSPAMarrl.net> wrote: >I am trying to make a 3 Kernel ROM adapter for the 64C. It requires a >27C512 eprom because each part is 16k in size, (Basic 8k/Kernel 8k) >49512bytes in size total. I pad the low end of the eprom 0000-3FFF >with 0's because it will not be used. because the binary must be >65536bytes in size to completely fill the eprom. One thing I did find >out was that Pin 1 (A15) must be Open Circuit which is NOT show in >that pic but is shown on the LEFT side. > >The adapter I am trying to use is : > >http://www.spacetaxi.bravehost.com/ELECTRON/EPROM-3W-SW.htm > > The one on the RIGHT. The page loads real slow for some reason. > >It says something about "A wire from Pin 13 & 14 to Switch-to (GND) If >I short out pins 13 (O2) and 14 (GND), the computer won't do anything. > >I can get the border & background to change the proper colors BUT no >Text is displayed. I tested each 16k section using a 27c128-16k eprom, >all three section of the 64k binary work PERFECT by themselves. > >Any idea what I'm doing wrong? This SHOULD work, I can's see any >reason why it wouldn't. > >TIA I'm just happy that it's working. Was driving me crazy because I could get the Background/Border Colors and that was it..My guess is because A13 was NOT in the socket is what the whole problem was.
From: Sam on 3 Aug 2010 19:06
On 3 aug, 23:34, DMackey828 <n2...(a)NOSPAMarrl.net> wrote: > On Sat, 31 Jul 2010 18:07:58 -0400, DMackey828 <n2...(a)NOSPAMarrl.net> > wrote: > My guess is because A13 was NOT in the socket is what the whole problem was. You are right, A13 must be connected for a 16 Kb configuration. If it's not connected you only load the first 8 Kb (the kernal) and not the second 8 Kb (basic) so you got a normal blue screen without text. SAM |