Search results

I'll don my firesuit and say it out loud: the performance of Alpha is largely an urban legend. In real life, it wasn't that much better than everything else available in a similar time-frame. I think this the belief exists for two main reasons: (a) the megahertz myth that was running at full...

If you want some more readable cint92 data, here's the netlib content filtered into a ODS spreadsheet.

I'm fiarly sure the QL didn't have an MMU, Ethernet, or SCSI, let alone DMA for the last two. And the 8-bit bus is a lot easier to handle than the wider bus of other 68k (the number of buffer and register chips in the 3/60 is staggering, as with bus sizing on a '020 you need to move that upper...

I think here you're comparing different things, and over-estimate the importance of laptops at the time. As you note later, the 68k was originally high-end. TL;DR: early 68k needed extra chips to be at feature-parity with later one, and laptops never use the highest-end CPUs. The original...

As you noted later in your post, it's connecting a FPGA to a '110. Re-creating a '110 would be even more complex than recreating a full '030, and we still don't have that as open-source gateware :-( The original idea was to create a FPGA-based motherboard with a CPU daughtercard (or two), and...

The Vcc and GND pins don't really count as signals, in the PGA package they are through-hole so they connect directly to the power and ground planes - not routing needed. You do need to decouple them properly, though. Not much of a problem on a dual-sided board, but if you want a cheaper...

I believe so, because if you ignore the direct-store interface, the 60x bus is similar to the 88110 bus (the original 88100 is quite different as it has split instruction and data busses and pretty much need a pair of 88200 to make a conventional workstation). There's some differences between...

Probably, but not certain, because of the direct-store (which the 601 had a different name for) interface. The 60x bus is more complex than a 68k bus, but not by an unreasonable amount. The main differences are (a) 64 bits (obvious!) (b) separate bus controls for Address and Data busses. (c)...

Did you find a viable option? At 5V, 16 Mbit SRAM are expensive and with big MOQ, while 4 Mbit are more viable but you'd need 32 of them - that's a large PCB, and I'm not sure what the signal integrity would look like with all those extra chips/traces. I've thought about it as well, but couldn't...

Yes, tag SRAM (which include comparators so they can do both storing and checking of tags) haven't been made in years, are expensive if you can find them, and won't help making bigger/better caches. Using a programmable device (i.e. FPGA) with embedded SRAM for tags (and external discrete SRAM...

An information that isn't very useful because of the cost, but that delights me that it simply exists, you can still get them from the continuation manufacturer: MC68882EI25AR (they even have 50 MHz parts in PGA if you're willing to spend >$120 on each...).

The best way is to use the onboard socket, but beware that a lot of '882 for sales are remarked and not necessarily what they pretend to be :-( For a stock 25 MHz LCIII, most PLCC '882 should be fine, but there's always a risk if the source is not reputable (either lower frequency '882 remarked...

ACT would probably work as an alternative for ALS, though they have different driver properties. @Addicted : A supply issue you might have had on the 74ALS640 seem to have been transient, as I see significant stock at MOQ=1 at Mouser. ALS are generally fairly available.

If you want authentic vintage, I don't know; if you want the functionality, someone did a redesign some years ago. So you can build your own. Original discussion thread here.

As far as I know, all XC68LC040 have the errata and none can support a FPU emulator to run regular 68k FPU code. You want to use either a full '040 (to get the hardware FPU, best option), or a newer MC68LC040 that can support FPU emulation (why do that if you can get a full '040 instead, I don't...

Common PC ones are well documented (the wikipedia links has some of them, though I can't vouch for reliability). For others, usually you need to dig out the manufacturer's documentation - bitsavers and similar are valuable resources, but searching for the appropriate document is usually tough...

DE-9 (being a bit pedantic here sorry) was common for video connectors at the time, including Sun's ECL monochrome devices and early PC standards (CGA, EGA, as you mentioned early VGA also used DE-9 rather than the since-ubiquitous DE-15). They may have wanted to share electronics and cabling...

On MC68000 (i.e. the SE), MC68030 (other than the IIfx, so SE/30 and IIsi) and Quadra, very direct. It exposes most of the CPU bus directly. The IIfx has some buffering to do weird things with the CPU clock, as the CPU run at 40 MHz but the PDS at only 20 MHz. The LC PDS is missing some...

Does the NuBusFPGA count as a "real-word NuBus card" ? :-) (and coming 30+ years after the fact, I don't think it counts, but honestly having that much space to play with is convenient for modern HW designer!). Anyway, there's (at least) two way of seeing the large size of the superslot (256...

Using a PDS slot instead of the 68k original socket doesn't make of a difference, maybe a bit more signal integrity issue but at the 68000 speed not really an issue. The PiStorm was designed for the Amiga, hence some of the choices. Using the approach to make a peripheral instead of a CPU is...