1581 on Vic-20?

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Kakemoms
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1581 on Vic-20?

Post by Kakemoms »

Is anyone here using the 1581 drive with a Vic-20? Which interface are you using and does it support "burst mode"? Can one save files on a 1.44Mb PC drive and read them on the 1581?
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Mike
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Re: 1581 on Vic-20?

Post by Mike »

Kakemoms wrote:Is anyone here using the 1581 drive with a Vic-20?
Not me, but IIRC orion70 and eslapion use one with their VIC-20s.
Which interface are you using
It works with standard IEC cabling.
and does it support "burst mode"?
On the VIC-20, the necessary hardware for burst mode isn't there. So no. Neither is it on the C64 - the C128 is the only computer ex factory to support burst mode as host. But you can install JiffyDOS on both drive and VIC-20 (or for the latter, use SJLOAD), and that combo will already be faster than burst mode, and for all type of file operations.
Can one save files on a 1.44Mb PC drive and read them on the 1581?
For complete *.d81 images, 1581copy does the job.

Some years ago, orion70 and I prepared two disk images (bible3.zip and pentateuch.zip) you may want to try out (you'll need +24K RAM expansion as well).
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orion70
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Re: 1581 on Vic-20?

Post by orion70 »

Mike wrote:Not me, but IIRC orion70 and eslapion use one with their VIC-20s.
Nope, not me - I use 1581 images on the SD2IEC device as anyone here I guess :).
Mike wrote:Some years ago, orion70 and I prepared two disk images (bible3.zip and pentateuch.zip) you may want to try out (you'll need +24K RAM expansion as well).
Excellent examples of D81 images, and great content too :wink:.
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eslapion
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Re: 1581 on Vic-20?

Post by eslapion »

Kakemoms wrote:Is anyone here using the 1581 drive with a Vic-20?
I do. I use JiffyDOS with this drive and it loads/saves lightning fast.
Which interface are you using and does it support "burst mode"?
Interface? IEC ... what else ??

As for the Burst mode, as Mike said, the VIC-20 doesn't have the hardware to support that.

I beg to differ with Mike on one thing, the C64 DOES have the hardware to support the burst mode (CIAs serial port) but it is missing at least 2 connections and the firmware to do it. I do believe a few years ago I found on the net a modded version of the C64 Kernal and a small schematic to get the burst mode for 1571 and 1581 on the C64.
Can one save files on a 1.44Mb PC drive and read them on the 1581?
You cannot save "files" but you can save disk images.

I use Simon Owen's SAMDisk located here: http://simonowen.com/samdisk/

Latest version is dated July 8th 2015.

Just put your files in a .d81 using DirMaster then write the image to a 720kb (you really get 800kb with the 1581) floppy.

Some high quality 1.44mb floppies can be formatted in the lower density used by non HD floppies but it's always better to use actual DSDD 3.5" floppies.

If you have no choice but to use HD floppies, you MUST cover the HD hole with OPAQUE tape. Some PC drives use an optical detector, some use a mechanical switch.
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Mike
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Re: 1581 on Vic-20?

Post by Mike »

eslapion wrote:[...]the C64 DOES have the hardware to support the burst mode (CIAs serial port)[...]
... instead of the VIAs with their bugged shift-register, yes.
[...]but it is missing[...]
... the entire /FSDIR logic. See the bottom (A8, A7, A6) of the linked-to C128 schematic on zimmers - 310378-3-left.gif.

That logic gets its signal from a register bit in the MMU, and as the MMU is de-activated in 64 mode, that logic also needs to "disappear" - for this reason the 128/64 signal is also routed to it. The /FSDIR signal is responsible to select the directions of the SRQ and DATA lines. The simpler hacks to connect the SRQ line on the C64 unfortunately interfer with tape operation. :(

...

Still the point remains - the 1581 works together with the VIC-20 without any issues, be it with the standard IEC protocol, or enhanced by JiffyDOS. Just not with burst mode.
merman
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Re: 1581 on Vic-20?

Post by merman »

Another tip.

Directory listings can take up a LOT of memory, if you don't have JiffyDOS or similar.

Use selective directory methods, e.g.

LOAD"$:*=P",device to get only PRG files

LOAD"$:D*",device to get all files beginning with D

LOAD"$:D?G=P",device to get all PRG files starting D something G

And so on
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eslapion
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Re: 1581 on Vic-20?

Post by eslapion »

BASIC V4 is also very nice for displaying a directory without loading it in RAM. The way it displays it is smarter than JiffyDOS because each file takes one text line.
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Kakemoms
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Re: 1581 on Vic-20?

Post by Kakemoms »

eslapion wrote:
Which interface are you using and does it support "burst mode"?
Interface? IEC ... what else ??
Well, the burst mode is actually IEEE, so it would suggest that it could be used with a IEEE expansion for the Vic-20?
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Mike
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Re: 1581 on Vic-20?

Post by Mike »

The fast serial protocol (a.k.a. "burst mode") is very similar to what Commodore originally intended to use as serial implementation of the (normally 8-bit-parallel) IEEE-488 interface. As you know, those plans were thwarted by the bug in the VIA shift registers, leading to the sloo-ooo-oow reimplementation with bit-banging.

If anything, those IEEE expansions provide that original 8-bit-parallel IEEE interface, for use with SFD1001, CBM8250, etc. They don't implement the 1571/1581 burst mode.
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eslapion
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Re: 1581 on Vic-20?

Post by eslapion »

Kakemoms wrote:Well, the burst mode is actually IEEE ...
Cough! cough ! cough!

Excuse me???

This...
Image

is the same as that...
Image

:roll:
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Kakemoms
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Re: 1581 on Vic-20?

Post by Kakemoms »

eslapion wrote:
Kakemoms wrote:Well, the burst mode is actually IEEE ...
Cough! cough ! cough!

Excuse me???

This...
Image

is the same as that...
Image

:roll:
Lol. This is the Vic-1112 expansion board for IEEE-488:
VIC-1112_interior.jpg
Very different from your random pictures. It contains two 6522. I have no idea whether it supports serial 488, which directs us back to the original question.

From the 1581 wiki page:
"Like the 1541 and 1571, the 1581 has an onboard MOS Technology 6502 CPU with its own ROM and RAM, and uses a serial version of the IEEE-488 interface. Inexplicably, the drive's ROM contains commands for parallel use, although no parallel interface was available."
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eslapion
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Re: 1581 on Vic-20?

Post by eslapion »

@Kakemoms
Concerning your photo, this cartridge provides a IEEE-488 disk drive parallel interface exactly the same as found on 2031LP and SFD-1001 drives with a different connector. They are fully electrically compatible so connecting one to the other just requires a cable with the proper connector at both ends.

On the C128(D), 1570, 1571 and 1581, the burst mode is only possible through the use of the special serial port built into the 6526 or 8521 and requires a DIN 6 pin connector. In see no such chips or connector in the above cartridge...

You know, 1BASE5 and 1000BASE-T are just 2 different versions of Ethernet. Why not just substitute one with the other ?

Added edit: you created a new type of interface and name too... "serial 488"...
I have no idea whether it supports serial 488
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eslapion
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Re: 1581 on Vic-20?

Post by eslapion »

To get back on track of the original subject of this thread, the 1581 can cause problems with the datasette of you have the early version of the ROM.
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