What to get to replace an A1000

[Vanfanel]

Upon doing some reading on the internet today, I discovered about how the American NTSC A1000's Denise chip can't do EHB modes. Opening up my case, I discovered that it is indeed the case with mine. That being said, what would you recommend as a replacement for it, considering its sole purpose is for gaming. Also, I already have an A1200, but have seem to have out of sync issues when older games use multiple audio channels, so I'm going for as compatible as possible.

Another thing I read was that the ECS should be fully compatible with OCS games, but that the A500+ couldn't run some games that an A500 could. Was the ECS at fault, or was that something else.

I suppose I could also just replace the Denise chip with one that does support EHB, but I'm still curious about this question. Thanks!

[fishy_fiz]

Unfortunately theres no absolute answer here. OCS/ECS/AGA all have some imcompatibility issues with some software. Theres some old games that wont run on OCS machines too (elfmania and stardust for 2 random examles). An a1200 + fast ram +whdload is probably the best compromise in my opinion.

Slightly off topic, but:

@anyone who knows:
As for some a1ks not having ehb modes, whats the story in regards to dual playfield displays? Are they limited to 3bit + 2bit for playfields? (where does the 6th bitplane come from?)

[Vanfanel]

I haven't tried WHDLoad yet on the 1200. Once my subway arrives and I install it, file transferring won't be such a pain, so I can get the installs for the games I'm having problems with, and see if that fixes the sync problem.

I suppose, if I wanted max compatibility with the 1k, it would need to be another OCS machine with KS1.3.

[Vanfanel]

Side question. I just found a Denise chip (8362R8) on eBay. Would this work in my 1k?

[NovaCoder]

An a1200 + fast ram +whdload is probably the best compromise in my opinion.

Yep I agree, a 1200 makes the best (and most compatible) Amiga gaming platform.  If you're having audio issues you might want to get that motherboards CAPS replaced + check for timing faults.

BTW file transfer will still be slow with the Subway, easiest solution is a CF PCMCIA card.   I'm currently transfering loads of WHLOAD games and demos over to my Miggy from my PC using this method and it's quick and painless.

[AndyLandy]

Side question. I just found a Denise chip (8362R8) on eBay. Would this work in my 1k?

That's another OCS Denise, it'll work, but not gain you anything. You'll want an 8373R4 for ECS modes. It should just swap in to your A1000.

[Matt_H]

It's only very, very old Denise chips (pre-OCS) that can't do EHB. My A500 has an OCS Denise (don't remember the exact part number but it's in the 836x range) and does EHB just fine. ECS Denise just adds the SuperHiRes and Multiscan (and Super72?) screenmodes.

[joekster]

Yes, that chip will work and enable ehb. BUT, do you really need ehb??? If you ask around, you might find a spare ehb denise from someone who upgraded to the super (ecs) denise. I might even have a spare one burried deep...

[psxphill]

@anyone who knows:
As for some a1ks not having ehb modes, whats the story in regards to dual playfield displays? Are they limited to 3bit + 2bit for playfields? (where does the 6th bitplane come from?)

All chips have 6 bitplanes, you need them for HAM. However they only ever had 32 colours. With an extra bitplane that was only usable for HAM and dual playfield, someone had the idea of making colour 32-63 the same as 0-31 but half the brightness. I'd have added the extra colour registers, but they probably ran out of space.
 

That's another OCS Denise, it'll work, but not gain you anything. You'll want an 8373R4 for ECS modes. It should just swap in to your A1000.

 
I thought you needed the ECS blitter as well, which is slightly harder to fit in an a1000.

[AndyLandy]

OK, you guys could well be right. I wasn't aware that the A1000 chips are different to even the A500 OCS Denise.

I do know that you can upgrade an A500 or A2000 from OCS Denise to the ECS one for the extra screenmodes. I thought EHB was only in ECS, but I could well be wrong on that.

[gertsy]

@Andy. There is a monkey on your head!  
Be careful.

[Kronos]

[nitpick]

Wouldn't a non-EHB-Denise actually be a Daphne ?

[\nitpick]

[Darrin]

As you're experiencing some problems with older games on your A1200 then you might want to look at a "Minimig v1.1".  That way you get a machine with a real 68000 CPU (which can be cranked up to 50MHz in the menu for any flight simulators, etc), OCS and ECS chipset, and you can run either the ADFs or WHDLoad from a Hard File on the SD Card.  You'll be able to get your whole collection of games on a 2 or 4GB card.

If you plan on using WHDLoad then get the 4MB version and not the 2MB one.

When MikeJ's FPGA Arcades appear in numbers then don't be surprised to see Minimig v1.1 machines appearing on eBay.

[desiv]

Feature-wise it was Daphne without EHB, but I believe it was Denise when they rolled it out...
Some of the earliest Amiga 1000's shipped in the U.S. had the non-EHB Denise.
You should be able to swap it with no problem, according to this thread:
http://eab.abime.net/showthread.php?p=413514

I can confirm that I did have an ntsc A1000 with the non-halfbright  denise chip. I dont know how early it was because I got it used. All I  did was swap out the denise for a newer one and halfbright worked.

EHB was available in OCS, it wasn't an ECS feature...

There are very few games that actually use it from what I can see-online.

desiv

[motrucker]

Both the A1000 I now use, and the unit I just sold will/would handle EHB. I remember reading that this problem was only with very early A1000 units.