Hi Gary, Have you made the changes for the WDC W65C02S6TPG-14 listed here http://www.westerndesigncenter.com/wdc/AN-002_W65C02S_Replacements.cfm ? If you haven't I would suspect that your address and data buses are going tri-state due to a floating BE pin. This was also discussed in the other N8VEM group here https://groups.google.com/forum/#!topic/n8vem/JL1ubJlH4HY . Cheers, Ian.
On Thu, Aug 28, 2014 at 11:10 PM, <[email protected]> wrote: > Good idea, I'll give that a try! Hopefully my Mouser order will arrive > tomorrow as well.... > > - Gary > > > On Wednesday, August 27, 2014 11:56:16 PM UTC-4, monahanz wrote: > >> See if you get the exact symptoms by switching around identical LS541’ s, >> LS244, etc. Often that can identify a bad one. Be very careful not to mix >> the current working arrangement. I usually number them before any moves. >> >> >> >> John >> >> >> >> >> >> *From:* [email protected] [mailto:[email protected]] *On >> Behalf Of *[email protected] >> *Sent:* Wednesday, August 27, 2014 8:09 PM >> *To:* [email protected] >> *Cc:* [email protected] >> >> *Subject:* Re: [N8VEM-S100:5064] 6502 CPU board questions >> >> >> >> John - >> >> Thanks for the hints. >> >> I'm able to input the IOBYTE correctly and echo to the screen. The >> monitor recognizes keyboard input and echoes them, just doesn't process >> correctly. I think it's a problem accessing RAM, as the symptoms are >> slightly different with various ram boards - probably upper address line as >> the I/O ports work fine. >> >> I have another batch of 74LS541's ordered, if that doesn't help I go thru >> the board wiring again! >> >> - Gary >> >> >> >> On Wednesday, August 27, 2014 6:09:47 PM UTC-4, monahanz wrote: >> >> Gary do you have all the jumpers as listed in the yellow table in the >> “normal” positions. . The fact that it can sign means you are almost >> there. Sounds like an address line problem or data I/O problem. After the >> signon have it input the SMB IOBYTE port and immediately output to console >> in a loop. Check ASCII character is always correct. >> >> Next do same inputting from Propeller input port. Next input, place in >> RAM, read back from RAM and display… >> >> >> >> John >> >> >> >> >> >> *From:* [email protected] [mailto:[email protected]] *On >> Behalf Of *[email protected] >> *Sent:* Wednesday, August 27, 2014 12:43 PM >> *To:* [email protected] >> *Subject:* [N8VEM-S100:5058] 6502 CPU board questions >> >> >> >> I'm trying to get the 6502 Master/Slave CPU board working - and seem to >> have hit an dead end. >> >> If anyone could confirm what they are using for monitor code, and jumper >> settings I'd be VERY appreciative! >> >> Background: >> >> Minimal system with SMB, 4mb SRAM, Propeller I/O and 6502 most recent >> Master/Slave PCB. The SMB, SRAM and Propeller boards work fine with Z80 >> and 8088 systems. >> >> All testing and assembly worked as expected following John's notes until >> the 28C64 was installed. >> >> I burned the 28C64 from the 6502mon.bin V1.0 file, with the code starting >> at 01000H in the 0000H --> 1FFFH space. 01000H thru 010FFH contains 00h as >> expected, and I can see the jump vector addresses in the top of memory. >> 0000H thru 0FFFH contain FFH as a fill character. >> >> I had to change the P31 jumper to connect 5-6 to get the monitor to sign >> on. Set up as a bus master (only cpu in system). >> >> Now I get the monitor to sign on and print the menu twice. It then >> accepts input characters but doesn't respond properly to any. Single >> letter commands like "A" just reprint the menu. Longer commands like >> D0000,0100 accept the full input and reprint the menu. >> >> CPU is a W65C02S6TPG-14 purchased thru a reliable source (Mouser) - and I >> have a second CPU (same source/batch) I've also tried. I've replaced every >> other IC except the 74LS541's (I only have a single spare - which I've >> substituted for every position). I've resoldered ever connection. I've >> tried both 28C64 and 27C64's for the monitor. >> >> - Gary >> >> -- >> You received this message because you are subscribed to the Google Groups >> "N8VEM-S100" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> For more options, visit https://groups.google.com/d/optout. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "N8VEM-S100" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> For more options, visit https://groups.google.com/d/optout. >> > -- > You received this message because you are subscribed to the Google Groups > "N8VEM-S100" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "N8VEM-S100" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
