Monthly Archives: August 2020

Support for another burst command added in IECHost

This morning I added support for reading the burst INTERLEAVE value out of a 1571 drive and expanded support of the burst READ command to read multiple sectors. The former returns the soft interleave value used by the 1571 to … Continue reading

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Two more burst commands implemented in IECHost

Today I was reading a bit about the Burst Command Instruction Set (BCIS) as documented in Commodore’s official user’s guide for 1570/1571 drives. I was intrigued by the lack of details within the documentation so I implemented two more burst … Continue reading

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A few notes re 1571

The 1571 ROM I am studying suggests that Commodore included a disk copy routine (perhaps taken directly from the 4040?) that they were probably going to enable again for the 1572 drive (dual-drive version of the 1571). Such routine is … Continue reading

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IECHost hardware mod to support the fast serial protocol and burst commands

This morning I did a quick modification to the IECHost PCB that enables it to use the fast serial protocol and burst commands with 1571 and 1581 drives. It just needs a bit of reflowing and cleaning, and then it … Continue reading

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Burst fastload command added to IECHost!

This morning I did some research on the so called “burst mode” supported by 1571 and 1581 drives. After a post-lunch walk, in the early afternoon I started coding the implementation of the burst fastload command, i.e. “U0″CHR$(31)”<FILENAME>”. By late … Continue reading

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Further researching for the 1571 drive

As I recently acquired a 1571 drive to expand the capabilities of my IECHost project, I thought I might not just stop at adding support for “fast serial” mode. In fact I am going to do some research on these … Continue reading

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Support for the “fast serial” protocol added to IECHost!

This morning I finished the implementation of the “fast serial” protocol in the IECHost firmware, that’s the one used by the C128 to communicate with 1571 and 1581 drives, using CIA’s shift register. The result is quite pleasing so far: … Continue reading

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Analyzing the “fast serial” bus protocol between a C128 and a 1571 floppy disk drive

Today I received the 1571 I had acquired on eBay. Having received the C128 yesterday, this afternoon, straight after work, I was eager to take a few traces of the communication between the two 🙂 The screenshot below shows that … Continue reading

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Make Chrome fully Dark

Today I am posting something a bit different than usual. I got this question asked a few times at work: “How did you get Chrome to use a dark theme?”. Well, the answer is two-fold. First change your theme to … Continue reading

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An unexpected fix to the Commodore Kernal

A while ago I was commenting on how trying to query the status message from a non-existing serial device would cause a deadlock inside the Commodore 64 Kernal, while it performs a bus turnaround. At the time I also commented … Continue reading

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