Yes but I have to make a new board... my pcb was planned for a w65c51 my other idea is to use the ftdi chip + cpld to make the processor "think" that he has a 6850 or a 6551 knowing that with the ftdi chip most of the control / status of the 65c51 or 6840 becomes useless On 18/10/2023 20:07, Gerrit Heitsch wrote: > On 10/18/23 19:28, didier_at_aida.org wrote: >> thanks for the information, I ordered a few from Poland >> but I'll have to reduce the speed of the board to 1..2 Mhz >> >> frankly I'm mad, I think I'll have to rebuild my board >> probably with a FTDI chip usb fifo... > > You're not limited to a 6551 and similiar when wanting to connect a > UART to a 6502. With some glue logic it should be no problem to hook > up a PC16550D UART (NatSemi) which then also comes with 16 Bytes FIFO. > Also, no annoying bugs I know of and you should be able to go higher > than just 2 MHz. > > Gerrit > > > >> >> after the other infamous bug I found in the 65c816 in emulation mode... >> >> thanks >> >> >> On 18/10/2023 17:26, Gerrit Heitsch wrote: >>> On 10/18/23 15:04, laughton_at_cyg.net wrote: >>>> It's my understanding that all 65C51's made by WDC are affected, >>>> but all other versions such as mos 6551 are free of the transmit >>>> flag bug. >>> >>> Yes, but those have other problems. The NMOS/HMOS 6551 will stop >>> transmitting the moment /CTS goes HIGH. That can be in the middle of >>> a byte being sent. This is documented in the data sheet. >>> >>> As far as I know, only the 65C51 (Rockwell for example) is behaving >>> one would expect. >>> >>> Gerrit >>> >>> >>> >>>> >>>> More on the bug on 6502.org, here: >>>> http://forum.6502.org/viewtopic.php?p=26524#p26524 >>>> >>>> -- Jeff >>>> >>>> On 2023-10-18 08:45, didier_at_aida.org wrote: >>>>> Hi All :) >>>>> >>>>> I made a board with a 65c816 and a 65c51 >>>>> I saw on the web that apparently the w65c51 has bug on the >>>>> transmit flag ... >>>>> is there a way to identify the w65c51 with or without bugs ? >>>>> I checked the plus4 rom code to check how the 6551 was programmed >>>>> >>>>> is this bug only on the w65c51 or also on the mos 6551 ? >>>>> >>>>> my goal was to study how to replace a mos 6502 by a 65c816... on a >>>>> commodore 8032 >>>>> have a board with ram + 64ext on the board and run at 1 Mhz on the >>>>> I/O >>>>> and faster speed while accessing the ram (8Mhz) >>>>> >>>>> thanks >>>> >>> >>> >> > >Received on 2023-10-18 22:00:15
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