d64it-vic 1.1alpha

[Strobe]

Hi, this is my first effort at a vic20 utility - a port of d64it to the vic.

I don't know if this is actually _useful_ to anyone .. but it is at least proof I can actually code something on a vic20 these days (I haven't had one for 20years).

It needs an 8k (or more) expansion to work.

http://www.kludgesoft.com/downloads/d64it-vic1.1a.prg

This is the (yet to be updated) page from the original d64it/d128it if you want to know what it does (which is pretty simple, it writes or reads d64 images to/from a real 1541 from another c= drive like a 1571/81/CMD).

http://www.kludgesoft.com/c64/d64it.html

Please note this is alpha stuff, and you need to be very careful with what drive you selected before hitting go, or it will wipe things happily writing sectors over your destination drive..

Comments welcome/encouraged.

Strobe

[RobertBe]

Thanks, Errol! I'll try it out on my VIC-20 system.

Truly,
Robert Bernardo
Fresno Commodore User Group
http://videocam.net.au/fcug

[eslapion]

Since I mostly use 1581disk to transfer commodore computers and PCs, d64it is very useful to me. However, it is very slow.

It seems the fact that all my Commodore drives and computers are equipped with JiffyDOS changes nothing to the speed problem.

Having d64it for the VIC-20 will be very useful as I won't have to use my C64 to transfer then use VIC-20 programs anymore.

[Strobe]

Since I mostly use 1581disk to transfer commodore computers and PCs, d64it is very useful to me. However, it is very slow.

Thanks for the feedback, it should be faster with jiffydos as it only uses stock kernal routines, but maybe the sector read/write is not speeded up by jiffydos? I don't have jd in my vic20 to really try it.
Actually I will try this jload thing I have seen, I do have JD in a 1541.

I considered making a modified version of d64it for an unexpanded vic, but that would be even slower again! (it would only be able to read & write a few sectors at a time, the current version reads/writes whole tracks).

I don't know much about other speeders, eg easyload whether they will work with normal kernal calls or if they just speed up load/saves.

Strobe

[Diddl]

Thanks for the feedback, it should be faster with jiffydos as it only uses stock kernal routines, but maybe the sector read/write is not speeded up by jiffydos?

Speed of a backup program depends on more than the data transfer speed.

Cause a floppy drive is very slow (5 upm) the sector ordering (interleave) is very important.

if you read sector 1,2,3 ... n you only can read 1 sector per rotation, this is only 5 sector per second.

For 21 sectors per track you need mor than 4 seconds to read a track independent of the bus speed. So jiffy has no influence.

---

If your bus speed need for example 10 sectors to transfer 1 sector, you optimize speed by reading every 11 th sector.

For faster bus speed you maybe can read every 3 th sector.

---

OpenCBM has a WARP protocol which sends automatically in optimal sector interleave. Cause floppy decides which sector will be read next. It takes alway next available sector after bus transfer.

[Strobe]

Cause a floppy drive is very slow (5 upm) the sector ordering (interleave) is very important.

if you read sector 1,2,3 ... n you only can read 1 sector per rotation, this is only 5 sector per second.

For 21 sectors per track you need mor than 4 seconds to read a track independent of the bus speed. So jiffy has no influence.

Of course you are completely right, and d64it reads sectors in order, not by interleave. So of course it takes over 2 minutes to read a disk.
I'll add that to my to-do list and look at implementing interleave into the 1541 read/write side.
I'm not sure how to handle different interleave for normal/JD drives, but I assume there are ways around that.

[nbla000]

Thank you for your effort, I will try it