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Search: Posts Made By: plasmab
Forum: support.Hardware Yesterday, 20:18
Replies: 84
Views: 7,509
Posted By plasmab
BTW I noticed a bug in your IDECS code.. ...

BTW I noticed a bug in your IDECS code..

assign IDE_CS[1:0] = ADDRESS[13:12];

Is wrong. They should never both be low. The correct code is..

assign IDECS = A[12] ? {~IDERANGE, 1'b1} :...
Forum: Coders. Asm / Hardware Yesterday, 18:13
Replies: 101
Views: 2,303
Posted By plasmab
When you do this kind of stunt on an 8 bit...

When you do this kind of stunt on an 8 bit machine you use the stack pointer for either the Source or destination and push/pop as appropriate. So it’s like having one Amiga address register that has...
Forum: Coders. Asm / Hardware Yesterday, 17:28
Replies: 101
Views: 2,303
Posted By plasmab
I know. But it’s a rough estimate. Lack of...

I know. But it’s a rough estimate. Lack of registers etc and only one accumulator... yeah I know.

But in the dumbest sense a copy from A to B is what I’m thinking of.
Forum: Coders. Asm / Hardware Yesterday, 17:01
Replies: 101
Views: 2,303
Posted By plasmab
I’ll take that figure. 0.8 MIPS. Sure mips isn’t...

I’ll take that figure. 0.8 MIPS. Sure mips isn’t a great measure. This is why Whetstones and Drystones exist.
Forum: Coders. Asm / Hardware Yesterday, 16:56
Replies: 101
Views: 2,303
Posted By plasmab
BBC doesn’t have video contention because of the...

BBC doesn’t have video contention because of the crack smoking way it’s video system accessed the bus. Somehow manages to access on both edges of the clock. It’s mad.

Of course the Stock BBC B has...
Forum: Coders. Asm / Hardware Yesterday, 16:49
Replies: 101
Views: 2,303
Posted By plasmab
It’s useful for me to see what difference a...

It’s useful for me to see what difference a change to bus timing makes. That’s about all.

The register readback thing is pretty standard across many architectures. Most operating systems kept a...
Forum: Coders. Asm / Hardware Yesterday, 16:24
Replies: 101
Views: 2,303
Posted By plasmab
I’m likely to trust sysinfo over the Motorola...

I’m likely to trust sysinfo over the Motorola marketing bumph though. What does AAIB say?
Forum: OT - Technical Yesterday, 16:18
Replies: 48
Views: 997
Posted By plasmab
That’s really why I think 8Mb is probably all you...

That’s really why I think 8Mb is probably all you need in an A500. AGA Amigas maybe more but 32mb in an A500 is not for playing retro games... it’s for trying to pretend your Amiga can play...
Forum: Coders. Asm / Hardware Yesterday, 16:03
Replies: 101
Views: 2,303
Posted By plasmab
Sysinfo reports 0.5mips for a stock 500... is...

Sysinfo reports 0.5mips for a stock 500... is that wrong?
Forum: Coders. Asm / Hardware Yesterday, 15:52
Replies: 101
Views: 2,303
Posted By plasmab
Sigh. People are taking this too personally. I am...

Sigh. People are taking this too personally. I am only interested in comparing the bus interface timing here. No that one CPU is better than the other. Why can’t people ever take what I say in the...
Forum: OT - Technical Yesterday, 13:56
Replies: 48
Views: 997
Posted By plasmab
Useful... I mean if you are using your...

Useful...

I mean if you are using your trying to use an A500 for email, social media, doing accounts, surfing the web... trying to pay your gas bill etc.

If you try to do the above (maybe do...
Forum: support.Hardware Yesterday, 13:29
Replies: 84
Views: 7,509
Posted By plasmab
Some do it right but even my latest TF530...

Some do it right but even my latest TF530 firmwares doesn’t ... I decided it was better to use the space for SPI rather than a comparison that is always the same value.
Forum: Coders. Asm / Hardware Yesterday, 13:27
Replies: 101
Views: 2,303
Posted By plasmab
68k details

The Atari STE... indeed [emoji14]

The Amiga 1000/500 didn’t do it properly. The ST uses the bus mastering system properly. The Amiga doesn’t. It just buffers the 68000 data bus from ram and makes...
Forum: Coders. Asm / Hardware Yesterday, 11:58
Replies: 101
Views: 2,303
Posted By plasmab
I already said this!

I already said this!
Forum: Coders. Asm / Hardware Yesterday, 10:53
Replies: 101
Views: 2,303
Posted By plasmab
The lack of a prefetch cache is part of my point....

The lack of a prefetch cache is part of my point.

The RAM chips themselves are 70ns ... I’ve replaced enough of them to know. The 280ns is with a refresh cycle which doesn’t happen all the time.....
Forum: Coders. Asm / Hardware Yesterday, 10:32
Replies: 101
Views: 2,303
Posted By plasmab
Yes. this is exactly the reason and it’s a poor...

Yes. this is exactly the reason and it’s a poor design of bus interface IMHO. when it’s executing instructions the bus is idle when it could have been preemptively reading something.

Sure it was...
Forum: Coders. Asm / Hardware Yesterday, 10:21
Replies: 101
Views: 2,303
Posted By plasmab
Or to put it another way. Modern CPUs have to...

Or to put it another way. Modern CPUs have to wait on the RAM being ready. The 68000 could barely make the ram work at 15% of what it was capable of (unless you were doing read modify write...
Forum: Coders. Asm / Hardware Yesterday, 10:01
Replies: 101
Views: 2,303
Posted By plasmab
It could have had so much better performance if...

It could have had so much better performance if it’s bus interface didn’t suck. And that’s my issue with it. Other CPUs got closer to their theoretical max performance because the bus interface was...
Forum: Coders. Asm / Hardware Yesterday, 09:45
Replies: 101
Views: 2,303
Posted By plasmab
That’s all I was saying. Right from the start.

That’s all I was saying. Right from the start.
Forum: Coders. Asm / Hardware Yesterday, 09:36
Replies: 101
Views: 2,303
Posted By plasmab
My point is .. and remains that the modern CPUs...

My point is .. and remains that the modern CPUs are limited by the RAM performance and the 68000 was limited by its own crappy bus interface. The number of. Cycles waiting is irrelevant. It’s the...
Forum: Coders. Asm / Hardware Yesterday, 09:28
Replies: 101
Views: 2,303
Posted By plasmab
68k details

Urgh. Ok. You will hear nothing against you beloved 68000. There is no point in discussion.

But if it was so good why is dead? It sucked. ARM has better latency and the x86 scaled better. Both ...
Forum: Coders. Asm / Hardware Yesterday, 09:06
Replies: 101
Views: 2,303
Posted By plasmab
68k details

I can put both chips on 10ns static RAM. The 6502 theorically maxes the RAM at 200MHz. The 68000 would need to go to 400Mhz... the first ARM maxes out at 100Mhz... same for the 040.




Rubbish!...
Forum: Coders. Asm / Hardware Yesterday, 08:38
Replies: 101
Views: 2,303
Posted By plasmab
Yes. I give you it’s an apples and oranges...

Yes. I give you it’s an apples and oranges performance comparison. Point remains... a plain 68000 takes 4 cycles to access the bus and the 6502 takes 2 base cycles. Plus the BBC makes its ram work on...
Forum: support.Hardware Yesterday, 08:14
Replies: 84
Views: 7,509
Posted By plasmab
Amiga 500 68K Accelerator - DIY

Almost all cards for the A500 behave like this.

We had a huge discussion about this on my channel and that’s when I realised 24 bit autoconfig wasn’t going to let people use my cards and older...
Forum: Coders. Asm / Hardware Yesterday, 00:41
Replies: 101
Views: 2,303
Posted By plasmab
68k details

Not the 6502 it doesn’t.

BBC B gets 0.5 mips at 2mhz. Same as the Amiga at 8mhz
Forum: Hardware mods Yesterday, 00:40
Replies: 3,420
Views: 296,700
Posted By plasmab
Kipper2k. Never found a way to program it

Kipper2k. Never found a way to program it
Forum: Coders. Asm / Hardware 20 August 2018, 22:47
Replies: 101
Views: 2,303
Posted By plasmab
My only issue with the 68000 CPU is that the bus...

My only issue with the 68000 CPU is that the bus takes between a week and a month to fetch a memory address. Other CPUs had better bus interfaces (even 8 bit ones!!) so they could get better...
Forum: OT - Technical 20 August 2018, 22:29
Replies: 48
Views: 997
Posted By plasmab
Maybe at some point. But until you get the bugs...

Maybe at some point. But until you get the bugs out with the simple bits you try to keep it cheap and repeatable.

EDIT: Anyways the idea was that someone could do an assembly run and sell them for...
Forum: OT - Technical 20 August 2018, 22:12
Replies: 48
Views: 997
Posted By plasmab
Experienced person guide on how to price hardware...

Experienced person guide on how to price hardware ....

https://www.youtube.com/watch?v=UwrkfHadeQQ

Basically 2.5 x cost of goods sold is the minimum to stay in business.

Cost of goods sold...
Forum: News 20 August 2018, 20:36
Replies: 26
Views: 964
Posted By plasmab
Yup. That’s why I don’t put simm sockets on my...

Yup. That’s why I don’t put simm sockets on my cards. To be compatible you need to slow things down too much
Forum: support.Hardware 20 August 2018, 20:05
Replies: 84
Views: 7,509
Posted By plasmab
Your theory is correct.. but you cant allocate...

Your theory is correct.. but you cant allocate your devices last because how would you know when all the other devices are done? there is no feedback.

This is why 24 bit CPUs are no use for the...
Forum: OT - Technical 20 August 2018, 10:06
Replies: 48
Views: 997
Posted By plasmab
Hobbiests, why do something you love, it upsets Amiga2000

I’m going to make one last attempt here for when this guy comes back...

What concrete action do you want me to take?

You seem to be suffering from a delusion that “they” need to solve your...
Forum: Hardware mods 20 August 2018, 08:04
Replies: 3,420
Views: 296,700
Posted By plasmab
I can’t support this because it will inevitably...

I can’t support this because it will inevitably lead to moaning when something’s not working. And I’m not going to spend time debugging hacks. There isn’t enough decoupling for this is one reason ......
Forum: Hardware mods 19 August 2018, 22:44
Replies: 3,420
Views: 296,700
Posted By plasmab
Terrible Fire Accelerators

No issue with it. The RAM isnt powered by the regulator.



I wouldnt recommend anyone build a TF530 right now. I'd wait for the TF534. There are many many stability fixes in it.

EDIT: but I...
Forum: Hardware mods 19 August 2018, 21:39
Replies: 3,420
Views: 296,700
Posted By plasmab
I thought about that but the design of the card...

I thought about that but the design of the card is flawed. It doesnt have a DTACK signal wired to the CPLD so we cant insert wait states while a refresh is happening.
Forum: Hardware mods 19 August 2018, 21:21
Replies: 3,420
Views: 296,700
Posted By plasmab
I think i've figured out what is going on with...

I think i've figured out what is going on with the Kipper2k card. the refresh cycle gets wound up in a main cycle every now and then and corrupts ram. TBH the ram card assumes perfect 4 clock cycles...
Forum: OT - Technical 19 August 2018, 18:50
Replies: 48
Views: 997
Posted By plasmab
I'd also like to add that my TF530 design was...

I'd also like to add that my TF530 design was aimed (as stated in many videos) to let you play frontier flat out. I don't see much point in anything else for an Amiga 500.

EDIT: I know people want...
Forum: Hardware mods 19 August 2018, 18:12
Replies: 3,420
Views: 296,700
Posted By plasmab
Yes.. and INTCYCLE is set when zii_access is low....

Yes.. and INTCYCLE is set when zii_access is low. and the BUS CPLD doesnt assert AS when INTCYCLE is low.

So once configured is set INTCYCLE no longer gets set low on access to E8xxxx.

EDIT:...
Forum: Hardware mods 19 August 2018, 17:20
Replies: 3,420
Views: 296,700
Posted By plasmab
I answered on stream. I dont allow acceses to...

I answered on stream. I dont allow acceses to E8xxxx to get to the 68000 bus until all cards are configured. its pretty simple.
Forum: OT - Technical 19 August 2018, 14:44
Replies: 48
Views: 997
Posted By plasmab
Excellent. Pay what Jens wants for his cards...

Excellent. Pay what Jens wants for his cards then. If you charge more you need to sell less units to cover the risk. Which is how he does it. I still dont think Jens makes much money.

And after...
Showing results 1 to 40 of 2269

 
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