Spectre party demo/Phenomena

[DonutKing]

Hi

Forgive me if this is a stupid question but I'm very much a rookie when it comes to amiga stuff... I'm pretty late to the game having only just picked up a second hand Amiga 1200 and 500 a month or so ago but I've enjoyed getting it up and running again and seeing what this thing can do

I'm trying to run this demo
http://www.pouet.net/prod.php?which=54337
(the download is an amiga executable file)

But on both machines I get strange vertical artifacts on the scrolling text- blue bars that extend from the text off the top of the screen. Kinda like puppet strings controlling the text. As you can see from the screenshot this isn't supposed to happen.

Yet in WinUAE with the same RAM and kickstart versions as my real Amigas it works perfectly. I've tried all sorts of settings and haven't been able to replicate the graphical artifacts in WinUAE.

Any ideas how I can make this work on a real system?
I see the comment there about dodgy code, but the demo is from 1989 so surely it must have worked on a real amiga at some point...?

This isn't a real problem or anything, I'm mainly just curious if there's any tricks I can try to make finicky stuff like this work... plus I like the demo

Thanks

[s2325]

Try to find and transfer ADF file, maybe it have something important in startup-sequence.

[Toni Wilen]

Perhaps it is OCS / ECS Agnus difference.

[DonutKing]

Well I can't find an image of the demo itself. I did find 3 demopacks with this demo:
http://kestra.exotica.org.uk/demo.php?id=14429
http://kestra.exotica.org.uk/demo.php?id=28287
http://kestra.exotica.org.uk/demo.php?id=14431

I wrote all 3 of them to floppy, and booted them in the 1200 and the 500. I get the same graphics glitches on all of them. Other demos work fine.

Originally Posted by Toni Wilen

Perhaps it is OCS / ECS Agnus difference.

Do you think it will only run correctly on a 500+/600?

[8bitbubsy]

Originally Posted by DonutKing

Do you think it will only run correctly on a 500+/600?

I think he meant the older Amiga 500 systems with the old 512kB Agnus chips, e.g. not Agnus 8372A on A500 rev 6A mobos and the like.

[DonutKing]

That must be right, as I tried it on a 1000 and it works perfectly.

[Photon]

Dots has one or two small bugs. But it's likely ECS chips causing this.

ECS instead of OCS usually causes non-kosher copperlists to give wrong modulo (jumbled graphics), and only in scrollers and such overscan attempts.

If someone wants to make a fix I think it's just a wrongly timed modulo 0, or set modulo to 0 at copperlist start.

[DonutKing]

Well here's something weird. On my A1000 Phoenix board with 8732A Agnus, this demo didn't work properly. One of the options you can install in the board is the U60 PAL/GAL chip which seems to do some address line hacking so you can get 1MB chipram + 1MB slowram on a 1MB Agnus.

When I set it up like this, the demo works perfectly... everything else is the same.
Some real black magic going on in that U60 chip

[Photon]

You will need to share your A500 specs, if we are to be able to answer.

If you had an A500 with no slowmem before and it works now that you have slowmem, then the answer is probably that the demo requires low chipmem to be free, which requires slowmem so the OS stuff can go there instead of occupying low chipmem.

Most pre-AGA demos work on A500 kick 1.3, 512k chip, 512k slowmem. Sometimes you have to turn off slowmem or external floppy to make them work. That's it. This is a description of the ultimate machine to make most demos work. It's really simple.

You can turn off slowmem/fastmem with HogFast

Now share with us your exact memory and kickstart specs.

You can find your hardware specs with RigInfo

[DonutKing]

It doesn't work properly on my 500 at all. It's a rev 5a with 1.3 kickstart. I have the trapdoor 512kb expansion and stock 512kb cchipram, but removing the trapdoor expansion makes no difference.



On the a1000 Phoenix though I have OCS Denise with Agnus 8372a and kickstart 1.3. I was running with 1MB chipram and the demo had same problems as before. I also reconfigured it for 512/512KB chip/slow and that made no difference. But now that I have installed U60 chip and have 1MB chip and 1MB slow it works fine. If I switch to kickstart 2.04 the problems return.


Just thought it was a bit strange I thought what Toni.Willen said above was correct, bit it seems that installing this U60 GAL chip makes the demo work on ECS Agnus.

What you are saying about low chipram needing to be free makes sense but I don't think it's the case here, as the demo works fine on standard A1000 with only 512KB chipram- but not on A500 with 512KB chipram and no slow/fast.

[Photon]

Originally Posted by DonutKing

What you are saying about low chipram needing to be free makes sense but I don't think it's the case here, as the demo works fine on standard A1000 with only 512KB chipram- but not on A500 with 512KB chipram and no slow/fast.

You have it there I think. Which kickstart does it work on, on the A1000?

My advice is still sound, but I think this demo has two requirements to work; kickstart to start correctly, and OCS [-compatibility] to display correct graphics.

I'm absolutely sure I've watched this on my A500/1.3/512/512 without glitches so you might try an alternative/fixed version, like this one if that's not the one you've tried with. No, I don't know that it's not the buggy/party version.

[DonutKing]

Which kickstart does it work on, on the A1000?

booting off kick 1.3 floppy

I will try that version you linked on my A500 and see if there is any difference


EDIT: Here is the logic for that U60 chip that makes it work on the Phoenix.

TITLE     PHOENIX BOARD RAM SELECT PAL
PATTERN   PHNXRAME.PDS
REVISION  E
AUTHOR    ANDREW J WILSON
COMPANY   PHOENIX MICROTECHNOLOGIES PTY LTD, ADELAIDE STH. AUSTRALIA
DATE      18/12/90 4.50 AM

CHIP RAMEN PALC22V10

;  1    2     3     4     5    6    7    8    9    10   11   12
 DTACK CASLI XRAMI CASUI A19  A20  A21  A22  A23  SELX SEL1  GND
;  13   14   15   16   17   18   19    20    21    22    23   24
  SEL2 GA4  GA3  GA2  GA1  GA0  CASU1 CASU0 CASL1 CASL0 XRAMO VCC
GLOBAL

EQUATIONS

/CASL0 = /CASLI * GA4

/CASU0 = /CASUI * GA4

/GA0   = /A23 * /A22 * /A21 * /A20 * /A19  ; GARY THINKS 080000 IS 080000
       + /A23 * /A22 * /A21 * A20 * /A19   ; GARY THINKS 180000 IS 180000
       +  A23 * /A22 * A21 * /A20 * /A19   ; GARY THINKS A80000 IS A80000
       +  A23 * /A22 * A21 * A20 * /A19    ; GARY THINKS B80000 IS B80000
    + A23 *A22 */A21 */A20 *A19 */SEL1 *SEL2 ; POOR GARY THINKS C80000 IS C00000
       +  A23 * A22 * /A21 * /A20 * /A19   ; GARY THINKS C00000 IS C00000
       +  A23 * A22 * /A21 * A20 * /A19    ; GARY THINKS D80000 IS D80000
       +  A23 * A22 * A21 * /A20 * /A19    ; GARY THINKS E80000 IS E80000
       +  A23 * A22 * A21 * A20 * /A19     ; GARY THINKS F80000 IS F80000
       + /A23 * /A22 * A21 * /A20 * /A19   ; GARY THINKS 280000 IS 280000
       + /A23 * /A22 * A21 * A20 * /A19    ; GARY THINKS 380000 IS 380000
       + /A23 * A22 * /A21 * /A20 * /A19   ; GARY THINKS 480000 IS 480000
       + /A23 * A22 * /A21 * A20 * /A19    ; GARY THINKS 580000 IS 580000
       + /A23 * A22 * A21 * /A20 * /A19    ; GARY THINKS 680000 IS 680000
       + /A23 * A22 * A21 * A20 * /A19     ; GARY THINKS 780000 IS 780000
       +  A23 * /A22 * /A21 * /A20 * /A19  ; GARY THINKS 880000 IS 800000

/GA1 = /A20

/GA2 = /A21

/GA3 = /A22

/GA4 = A23 * A22 * /A21 * /A20 * /A19 * SEL1 * SEL2 * /DTACK
     + /A23 * /A22 * /A21 * A20 * A19 * SEL1 * SEL2 * /DTACK
     +  A23 * A22 * /A21 * /A20 * /SEL1 * SEL2 * /DTACK
     + /A23 * /A22 * /A21 * A20 * SEL1 * /SEL2 * /DTACK

/XRAMO = A23 * A22 * /A21 * /A20 * /A19 * SEL1 * SEL2
       + A23 * A22 * /A21 * /A20 * /SEL1 * SEL2         

/CASL1 = /CASLI * A23 * A22 * /A21 * /A20 * /A19 * SEL1 * SEL2 * /DTACK
       + /CASLI * /A23 * /A22 * /A21 * A20 * A19 * SEL1 * SEL2 * /DTACK
       + /CASLI * A23 * A22 * /A21 * /A20 * /SEL1 * SEL2 * /DTACK
       + /CASLI * /A23 * /A22 * /A21 * A20 * SEL1 * /SEL2 * /DTACK
      
/CASU1 = /CASUI * A23 * A22 * /A21 * /A20 * /A19 * SEL1 * SEL2 * /DTACK
       + /CASUI * /A23 * /A22 * /A21 * A20 * A19 * SEL1 * SEL2 * /DTACK
       + /CASUI * A23 * A22 * /A21 * /A20 * /SEL1 * SEL2 * /DTACK
       + /CASUI * /A23 * /A22 * /A21 * A20 * SEL1 * /SEL2 * /DTACK
       
; IF SEL1 AND SEL2 (PINS 1&2 AND 3&4 OF L55) ARE HIGH THEN TWO BLOCKS OF 512K
; APPEAR AT 180000-1FFFFE AND C00000-C7FFFE. IF SEL1 IS LOW (LINK INSTALLED)
; THEN ONE 1MEG BLOCK OF MEMORY APPEARS AT C00000-CFFFFE (I HOPE). IF SEL2 IS
; LOW THEN MEMORY APPEARS AS ONE 2MEG CONTIGUOUS BLOCK FROM 000000-1FFFFE.


SIMULATION

;TRACE_ON 

 
;TRACE_OFF

[8bitbubsy]

; Poor Gary Thinks C80000 Is C00000