Hello, * On Tue, Sep 08, 2020 at 10:59:55AM -0500 vossi wrote: > Hi, I added the ROM, Disassembling, manual, flyer, card to my page: > mos6509.com thank you for the dump. I am happy to see 6809 assembly again. All vectors other then the RESET vector point to $FFFF. Thus, it seems, it does not make use of FIRQ, IRQ, SWI (2,3) or NMI at all! That's unusual. At a first glance, I thought you combined the ROMs in a wrong order (because the RESET vector pointed to $4DF1) until I remembered that the 6809 is big endian, not low endian like the 6502, so the RESET points to $F14D instead, and it makes sense now. ;) Do you have any more info? I see the following bigger chips: 1. MC6809P (the CPU) 2. MC6821P (PIA) 3. An EPROM (?) on top of the MC6821 (2716, if I read it right)? Do you know its content? 4. NEC D416C-2 (16K x 1 DRAM) x 8, resultig in 16 KB of RAM. 5. MC68488 (GPIB buffer, that is, the IEEE 488 transceiver) 6. Many additional small ICs (mostly LS-TTL) Did I miss any important chip, especially some ROM, RAM or I/O? I think it might be interesting to find out which chip is where in the memory map. Regards, Spiro. -- Spiro R. Trikaliotis http://spiro.trikaliotis.net/Received on 2020-09-08 23:00:03
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