how to speed-up a Disk drive using a Vic-20

[nbla000]

Hi, there is a way to speed-up a 1541/1541-II/1581 drive using a Vic-20 like the C64 does with a program or a cartridge?

I remember a routine that you must send to the drive so it works fast unless you switch off or reset it.

I've read on JiffyDos for Vic-20 and Drives replacements but i don't like to modify hardware, i use Zap loader or Action replay MK 6 for the C64, there are similar things for the Vic-20?.

[Schema]

Yes, you can send "UI-" to a 1541 to get a slight increase in speed when using it with a VIC20.

There was a Turbo Load program for the VIC20 in an old issue of Compute's Gazette - I can't remember which one, unfortunately.

[GreyGhost]

Turbodisk and Turbotape were both published in July 1985 issue of Compute's Gazette for the Vic and the 64,and the programs can both be found in the Gazette disk archive.

[nbla000]

I've tested this 1541 only fastloader for vic-20 using 3 or more kb expansion, but doesn't work properly on vice with true drive emulation, i will test it on a real Vic-20 next Week-End.

Looking for a Vic-20 Fastloader around the web i've discovered this link:

http://www.cs.tut.fi/~albert/Pu-239/vimm/

Where there is a very impressive Vic-20 demo Copyright © 2000 Pasi Ojala, Anders Carlsson.

Carlsson?!?! are you?

Looking the notes of the first demo it says:
This starting part also detects the video system and installs the first music and the 154x/157x/1581 fastloader, which is based on Marko Mäkelä's fastloader.

In the sources there is an assembler file "loader.asm", few row code:

Code: Select all

...
;---------------------------------------
; FOR 1581
;---------------------------------------
;acsbf8	= $03	; job for buffer 1 (not used directly)
trkbf8	= $0d	; track for job 1
sctbf8	= $0e	; sector for job 1

;ciapa	= $4000	; (not used directly)
ciapb	= $4001
ledon	= $cbcc	; activity led on: $cbcc, off: $cbc3
ledoff	= $cbc3	; or using the job queue:  on $94 / off $96

;---------------------------------------
; FOR 1540/41/70/71
;---------------------------------------
acsbf	= $01	; access to buffer 1
trkbf	= $08	; track of buffer 1
sctbf	= $09	; sector of buffer 1
iddrv0	= $12	; id of drive 0
id	= $16	; id

via1pb	= $1800
via2pb	= $1c00

;---------------------------------------
; For both 154x/7x and 1581
;---------------------------------------
buf	= $0400	; sector buffer (for job 1)
datbf	= $14	; databuffer - temporary (on 1581 sector for job 4)


drive	cld
	lda $ff54	; Execute Job -routine entry in the jump table
	cmp #$4c	; jmp abs	- probably exists
	beq drive1581
	cmp #$6c	; jmp (abs)	- probably exists
	beq drive1581
	jmp drive1571

name	ds.b 8
...

very interesting true?

There is any assembler coder that may use these sources to made a very first 154x/157x/1581 fastloader for the Vic-20?

HERE there are sources of the unexpanded version loader too!!!.

[carlsson]

I was not involved in the fastloader, but perhaps it can be extracted into a turbo on its own.