68040 cache accelerators

[luckybob]

I've been toying around with my 660av recently, and a thought occurred; Instead of fighting tooth and nail over accelerator cards, why can't we "remake" some of them? Case in point: the quad-doubler http://www.everymac.com/upgrade_cards/sonnettech/quad_doubler/quad_doubler_50.html

A deeper look shows 040 upgrade cards for 030's from people such as daystar. I was surprised to see that some of these models included a L2 cache memory. From what I know of X86 systems of the same vintage, having a nice L2 cache improved performance by a large margin. The a 486 with a proper motherboard could accept 1mb of cache! Long story short, most people had 256kb of L2, simply because more was not cost effective for the average user. This is 2014, memory is stupid cheap now.

Getting to my point, how hard would it be to re-create the quad doubler? I'm armed with an associates in EE but I recognised real quick I was out of my league here. A doubled' 040 with 1mb L2? Am I silly for even dreaming of such a beast? as for cost, I'm sure those "Amiga people" have money. :lol:

 

[CelGen]

There's stuff like GAL's and multiple layers which are nearly impossible to reverse engineer without destroying the part.

 

[luckybob]

Well, if you are making a new 030 > 040 accelerator yes. But I was mostly referring to the quad doubler. I only referred to the other upgrades because they included L2 cache with the 040 upgrade.

I'm referring to this guy:

http://www.micromac.com/products/quadra_cache_cards.html The one they mention for the 660av would be wonderful. Also by today's standards and prices, I'm sure we could fit more than 128k on the pcb.

more info:

http://lowendmac.com/tech/l2cache.shtml

 

[luckybob]

relevant:

http://www.nextcomputers.org/forums/viewtopic.php?p=17825&sid=9e873dc689eab973e0d6f7e317227826

 

[Unknown_K]

I seen one of those 68040/50 accelerators sell for the NEXT system on ebay years ago for many hundreds of dollars.

Cache does speed up 040 systems, my 68050/50 in a Quadra 950 with cache is pretty dam fast. You could buy cache upgrades for 040 systems with PDS slots.

 

[luckybob]

exactly. Having a large cache is also a good thing if you have a large amount of ram as well. And in this day and age who DOESN'T max out (or beyond) the memory in their 0x0 system? I know what I'm asking for DOES EXIST, and I'd love to be able to help make a batch of these add-on's for people that want to add one to their 040 system. For the people who have the compact 040's. I can't find the website right now but I remember the performance increase to be the range of 20-25% for 128k.

 

[register]

When the Performa / LC 475 was new I followed news regarding L2 cache cards to accelerate the machine. My impression was that general stability issues were the price to pay for some performance gain, no matter which make of L2 cache you purchased. As far as I understand the software was not capable to take properly advantage of the added cache. My computer dealer advised me against buying a cache upgrade. In case someone has better experience with 040 cache modules, let us know, please.

However, instead I invested in the first 32 MB RAM module I could get (a beautiful Motorola marked one). Unfortunately this nicely trimmed machine with a full 040/33 has been stolen in 2010. If anyone of you comrades comes across a Performa 475 with a slide switch to select 25/33 MHz clock speed, the switch fitted accurately into a cutout in the the rear PDS slot cover and secured with two tiny slotted pan head screws made of brass, notify me, please. The machine has quite some history, as it was my very first Macintosh Liberation, saved from scrapping back in 1995 (!).