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MEGA65 / mega65-rom-public

MEGA65 ROM public issue reporting
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IEC support for SD2IEC works unreliably in Mega65 mode #71

Open sir-lazarus opened 10 months ago

sir-lazarus commented 10 months ago

Platform MEGA65, ROM 920377 and newer:

When I use my SD2IEC device on my MEGA65's IEC port in Mega65 mode, it works unreliably. At first glance it works. But loading is very slow and when I load larger size files it doesn't stop loading. I loaded data from .d81 and .d64 Image files at 40 MHz and 1 MHz with the same behavior. Everything is slow as expected when switching to 64 mode, but works fine. So no issue in 64 Mode.

Everything works fine with the C64 Core, especially with Jiffydos.

The issues are only in Mega65 mode.

dansanderson commented 10 months ago

MEGA65 mode has IEC timing issues across the board, unfortunately. Printers and non-1581 drives have issues from MEGA65 mode. It's one of the last remaining unfinished areas of the ROM.

sir-lazarus commented 10 months ago

Yes I know. When this topic is on the bench, support the JiffyDOS protocol would be awesome, because SD2IEC supports this.

eilers commented 2 weeks ago

I have a problem with my 1581 Replica. This Replica uses original chips and a (afaik) correct replication of the original 1581 mother board. I would expect that it behaves equally as an original 1581 from commodore. But I cannot prove that as I don't have an original device for comparison.

Problem description (versions see below):

The drives works without problems using the C64-core as well as within the C64-Mode on the Mega65-Core.

When I use a recent MEGA65 ROM and for instance use the DIR command, the green light on the drive lights up but nothing happens. The drive is not spinning up or anything else happens. Only the DIR command ist blocking the Mega65. Possible reason for not spinning up is the fact that the 1581 keeps the directory in memory.

When I use the original prototype ROM for the C65, the behavior is different: The DIR command does not stuck and shows the directory. Loading of files with DLOAD seems to work, but was not extensively tested.

Versions:

C64-Core: WiP-V5.1-RC2 Mega65-Core: 0.96 3c10488 Mega65 ROM: 920404 C65 ROM: 0.9B.910828 Mega65-Board: R3

Picture of the Board of the 1581:

Source: Similar to https://diychris.com/product/1581-252326-replica/ Please note: I replaced the 6502 on the picture with one from an old 1541. The replaced 6502 is from 1984. The one on this picture was definitely a fake as the numbers make no sense.

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