Search found 74 matches

by AtariMega125
Thu Aug 19, 2010 4:09 pm
Forum: Hardware
Topic: 2 Computers 1 monitor switchbox
Replies: 7
Views: 2097

Re: 2 Computers 1 monitor switchbox

I use a standard VGA switchbox with 2 Atari Mono to VGA adaptors that I've made myself. And an RJ11 switchbox for the keyboard and mouse.
by AtariMega125
Thu Aug 19, 2010 1:01 pm
Forum: Hardware
Topic: Reverse engineering of some ICD Link adapter
Replies: 175
Views: 25177

Re: Reverse engineering of some ICD Link adapter

Ok, here are the photos: https://sites.google.com/site/atarimega125/_/rsrc/1282222209324/adscsi/AS3.JPG?height=240&width=320 https://sites.google.com/site/atarimega125/_/rsrc/1282222127716/adscsi/AS1.JPG?height=240&width=320 https://sites.google.com/site/atarimega125/_/rsrc/1282222277834/ads...
by AtariMega125
Wed Aug 18, 2010 4:05 pm
Forum: Hardware
Topic: Reverse engineering of some ICD Link adapter
Replies: 175
Views: 25177

Re: Reverse engineering of some ICD Link adapter

AdSCSI ST and AdSCSI Plus ST can over 1GB. Can handle removables, so very likely SCSI CD ROM drives (didn't see it specifically there). No parity support. The later versions of AdSCSI and all ADSCSI Plus cards(I think) handle parity. The ADSCSI micro definitely doesn't . I use my ADSCSI Plus with a...
by AtariMega125
Wed Aug 18, 2010 3:46 am
Forum: Hardware
Topic: Reverse engineering of some ICD Link adapter
Replies: 175
Views: 25177

Re: Reverse engineering of some ICD Link adapter

According to my experiences and measurings, Quantum SCSI drives work fastest with Mega STE internal adapter. Close to max speed of DMA chip (1250 KB/sec). 1298 K/S , 14ms average access time is what I just measured from From my Mega STE and an incredible 1438 K/S, 15ms average access time is what I...
by AtariMega125
Tue Aug 17, 2010 12:17 pm
Forum: Hardware
Topic: Reverse engineering of some ICD Link adapter
Replies: 175
Views: 25177

Re: Reverse engineering of some ICD Link adapter

I don't agree that SCSI drives in range 1GB-30GB are rare now. In second hand shops I still can find them at good price. Plus, nothing lasts forever, so it's good to have chance for repairing devices or replacing wwith equivalent. I was thinking of smaller drives. 30mb - 1gb. I have 2 quantum light...
by AtariMega125
Tue Aug 17, 2010 2:29 am
Forum: Hardware
Topic: Reverse engineering of some ICD Link adapter
Replies: 175
Views: 25177

Re: Reverse engineering of some ICD Link adapter

I would study this first, the ASCS/DMA guide which includes a the schematic of a ASCI to SCSI generic host adaptor. This is the basic concept of the ASCI/SCSI host adaptor and IDE, Supra and others built on it. I use an ASCSI Plus which probably does everthing the Link 2 does but in a larger form fa...
by AtariMega125
Mon Jun 28, 2010 11:48 pm
Forum: Coding
Topic: midi ports programming
Replies: 66
Views: 13312

Re: midi ports programming

i've the book too , but which exact title do you selcet.. or talk about? charles The midi programming book I use is called "MIDI programming for the Macintosh" by Defuria and Scacciaferro. All the source code examples are in Pascal which I don't do so I just use it for a MIDI reference. I...
by AtariMega125
Sat Jun 26, 2010 1:49 am
Forum: Coding
Topic: System requirements for an ST development machine
Replies: 16
Views: 4107

Re: System requirements for an ST development machine

@lp I have the source code already and am familiar with the dadhacker blog which is very interesting reading. Every Atarian should take a look at it sometime. Madmac does live up to it's claim of being "blindingly fast". My assemble time at the moment at 16mhz--both on the Mega Ste and Ste...
by AtariMega125
Wed Jun 23, 2010 11:12 pm
Forum: Coding
Topic: midi ports programming
Replies: 66
Views: 13312

Re: midi ports programming

thats a 'real time' recorder ,, not a 'midi time' recorder. charles Or maybe a "real time midi recorder". Midi is a protocol for transfering data. What you do with the data is only limited by your interest, ability and imagination. Notator really does a very good job as a realtime midi re...
by AtariMega125
Wed Jun 23, 2010 12:49 pm
Forum: Coding
Topic: midi ports programming
Replies: 66
Views: 13312

Re: midi ports programming

a midi device is step based pulses per quarter note Yes, if we are talking about drum machines. PPQ is just a reference. At 120 BPM, 1/4 note equals 1 beat, PPQ=KHZ/2. so even if you bumped up your clock its really unaffectfull , we just simulate going fast or going slow , the clock rate has no gen...
by AtariMega125
Wed Jun 23, 2010 2:01 am
Forum: Coding
Topic: midi ports programming
Replies: 66
Views: 13312

Re: midi ports programming

There is a clock. It is used to give midi events a time reference. Just like you can, say for example, look at your watch when you arrrive at a certain place and write the time in a notebook for future reference if you want to arrive at the same place at the same time another day, my sequencer recor...
by AtariMega125
Fri Jun 18, 2010 3:03 am
Forum: 680x0
Topic: timer a emulation xbtimer and rte
Replies: 64
Views: 10269

Re: timer a emulation xbtimer and rte

i'm just guessing but the code should save the registers cause the xbios call trashes registers , no?? charles The Xbios functions, if used correctly should take care of the registers they use internally. If you disassemble them--I've only done this for the midi interupt handler--you will see that ...
by AtariMega125
Wed Jun 16, 2010 2:07 am
Forum: Coding
Topic: midi ports programming
Replies: 66
Views: 13312

Re: midi ports programming

charles wrote:
the only trouble is under steem emulation timer 'a' won't function right.



:roll: :roll: :roll: ?????????? Timer A works fine under steem. If you read my previous posts , I have more stability under steem than on a real Atari ST.
by AtariMega125
Tue Jun 15, 2010 3:53 am
Forum: Coding
Topic: midi ports programming
Replies: 66
Views: 13312

Re: midi ports programming

I am not going to post my rapidly evolving code which I assemble 10 to 20 times a day when I work on it but the basic algorythm is much simpler than the code you quoted. The xbios interupt routine updates a 32 bit click word by 1 on every interupt during recording and during playback compares the cl...
by AtariMega125
Tue Jun 08, 2010 12:56 am
Forum: Coding
Topic: midi ports programming
Replies: 66
Views: 13312

Re: midi ports programming

The clock of my sequencer is the 68901's timer A which is not used by the system and generates an interupt at each tick which updates the clock longword by 1 at each interupt. When recording, the midi vector stores the clock longword with the midi status byte. On playback, a different timer interupt...
by AtariMega125
Mon Jun 07, 2010 5:29 pm
Forum: Coding
Topic: midi ports programming
Replies: 66
Views: 13312

Re: midi ports programming

would you find it at all crazy if i tryed to do the similar project? in fact made my own version of scratch pad? charles Not at all as long as you don't ask me for my code or copy my interface. And I don't know that "Scratchpad" is the final name for my sequencer, it is just a working nam...
by AtariMega125
Mon Jun 07, 2010 3:35 pm
Forum: Coding
Topic: midi ports programming
Replies: 66
Views: 13312

Re: midi ports programming

Ok, here is a photo of the beast in develpment which I have gone as far as naming "Scratchpad" because it is a simple sequencer like the Alesis MMT-8 or the built in scratchpad sequencers on some midi keyboards. http://sites.google.com/site/atarimega125/_/rsrc/1275924127289/scratchpad/Scra...
by AtariMega125
Fri Jun 04, 2010 3:59 am
Forum: Hardware
Topic: Internal Ultrasatan cable for Mega STe/STacy
Replies: 137
Views: 24588

Re: Internal Ultrasatan cable for Mega STe/STacy

Alright, just looking at the prices for passive cables, I will commit to one active cable for a Mega 4 St. I am in no hurry at the moment and if jookie needs partial payment to buy parts to build it, it is no probem--he sounds like a guy as busy as I am. And if there is information lacking on the pi...
by AtariMega125
Wed Jun 02, 2010 10:55 pm
Forum: Chat forum [ENG]
Topic: New build PC and retro-computer support.
Replies: 7
Views: 1215

Re: New build PC and retro-computer support.

I stopped reading when when you said Amigas ............ :mrgreen: :wink: :P So silly, you have no idea what you're missing. And would you be so prejudiced against all my midi equipment as well?? And you didn't miss much, Amigas was the second to last word. And maybe I was referring to some latina ...
by AtariMega125
Tue Jun 01, 2010 8:22 pm
Forum: Chat forum [ENG]
Topic: New build PC and retro-computer support.
Replies: 7
Views: 1215

Re: New build PC and retro-computer support.

In the PC world, I only use laptops these days and keep one retro thinkpad for the serial and parallel ports. The parallel is hooked up via a db 25 switchbox to my Mega 4 for file transfers with parcp and my rom burner which has a parallel port connection and my satellite tv box is connected to the ...
by AtariMega125
Tue Jun 01, 2010 12:43 pm
Forum: Coding
Topic: midi ports programming
Replies: 66
Views: 13312

Re: midi ports programming

(the 68901, which you are calling 16901) Just a typo. Hans Thanks for the insight. I played around with trying to disable the interupt by clearing the interupt enable bit of the interupt of the 68901 and it didn't work and then I tried to leave the interupt enabled and just substituted a vector tha...
by AtariMega125
Tue Jun 01, 2010 4:11 am
Forum: Coding
Topic: midi ports programming
Replies: 66
Views: 13312

Re: midi ports programming

Sorry but I'm not interested in collaborating. This is a personal project. I don't mind discussing midi and 68000 assembly but that's as far as it goes. The 68000 code example you posted was appreciated. I found similarities and differences with my code that were interesting. I'm trodding a well wor...
by AtariMega125
Tue Jun 01, 2010 3:10 am
Forum: Coding
Topic: midi ports programming
Replies: 66
Views: 13312

Re: midi ports programming

your basically replacing what they made with the exact same thing My vector time stamps the midi data and puts it into an array for playback at a 10khz clock rate. The Atari routine just buffers it. It is not the exact same thing at all. accurete math is nessesary , u need to learn how to do a long...
by AtariMega125
Tue Jun 01, 2010 1:23 am
Forum: Coding
Topic: midi ports programming
Replies: 66
Views: 13312

Re: midi ports programming

Alright, the bug has been quashed by the following: I read a little more of the "Hitchhikers Guide to the Bios" and used Xbios function 34 to get a pointer the midi vector which is a subroutine of the keyboard/midi vector stored at $118 and instead of doing the whole interupt handler, I ju...
by AtariMega125
Mon May 31, 2010 8:34 pm
Forum: Coding
Topic: midi ports programming
Replies: 66
Views: 13312

Re: midi ports programming

STeem piggy backs St midi onto PC midi and midi data is first handled by the pc and then passed onto Steem. That adds the time it takes the PC to process the midi to the STs timing. There is no way you'll get the same timing. I am writing the realtime midi functions in 68000 assembly to get the fast...

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