tried on the MICRO KIM 1 and 2 REPLICA 1 4v with rockwell 6502 2.8 / 3v with synertek it is clear that there are less components on the bus of these 2 machines changing the 6502 with a higher high level does not change the instability of the replica 1 tenth edition... these machine are rebuild made by Vince Briel, the micro kim and the replica 1 TE are working fine the replica 1 tenth edition is a nightmare... a finger around the propeller reset the 6502 every 2s (about) never found a solution... I thought that changing the 'high' level could solve the problem... on the replica 1 te the 5v->3.3v is done with 74ls245 + 1k resistors on the replica 1 tenth the 5v -> 3.3v is done with 1k resistors directly on the bus this second replica is about to be reduced to a stack of component + pcb for the trash :( On 06/11/2016 15:13, Gerrit Heitsch wrote: > On 11/05/2016 09:37 PM, didier derny wrote: >> while checking some signals on the 6502 of my 8032 motherboard >> I found the 'high' level rather low 2.5v (I expected around 4v...) >> >> so I took my SYM1 board and tested several 6502 >> MOS 6502 around 4v >> Rockwell 6502 around 4v >> Rockwell 65c02 around 5v >> Synertek 6502 around 2.5v >> CM630 around 4v (bulgarian clone) >> >> I tried several 6502 of each type... > > Since I was curious and able to test it... A few years ago I built > myself a replica of the EMUF232 on a perfboard (was a real pain in > the...). That's a 6502 system with 2 x 6522, 1 6551, 32KB RAM running > at 1.8432 MHz. As a CPU I used a SY6502A, datecode 8047. > > When checking the address lines on the scope today, the CPU produces a > HIGH of 3.5-3.7V. So it can't be Synertek in general unless the > drivers are less powerful than Rockwell and MOS and your board has > more load on the lines. If possible, check the SY6502 in another > board, maybe a 1541. > > Gerrit > > > > > > > > > > Message was sent through the cbm-hackers mailing list Message was sent through the cbm-hackers mailing listReceived on 2016-11-06 21:00:02
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