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 22:00:09
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