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Posted By

JamesC
on 2006-02-26
00:32:02

JiffyDOS Beta - Product Testing

Hello everyone! I received the Plus/4 and C16 JiffyDOS Beta in the mail today, so I did some testing.

First, I grabbed some software and did some "benchmarks" on the standard Revision 5 Kernal with a 1551 and a 1541:

Hitchhiker's Guide: 30 seconds on a 1551, 103 seconds on a 1541. This was measured from the time I pressed Y at the "Loading from a Commodore 1541?" prompt, til I got the interpreter prompt allowing me to type.

Saboteur: 54 seconds on a 1551, 109 seconds on a 1541. This title was picked because it's probably the longest single program file I have the original disk for (173 blocks).

General Ledger (InfoDesigns/Commodore): 32 seconds on 1551, 52 seconds on 1541. This was measured from the time I pressed Shift-Run/Stop til the date prompt. This title was selected due to its' heavy copy protection.

Superbase: 59 seconds on 1551, 125 seconds on 1541. Manually loaded "SB",8,1 and measured from the time I pressed Return til the time I was asked to insert a data disk. This title was selected because of intense disk access and custom program loader.

I then loaded the same titles on a JiffyDOS-equipped 1541, but still on the standard Plus/4 Kernal. Load times should have been the same, but were actually about 3% faster:

Hitchhiker's Guide: 100 seconds (3 seconds faster)
Saboteur: 105 seconds (4 seconds faster)
General Ledger: 50 seconds (2 seconds faster)
Superbase: 120 seconds (5 seconds faster)

I then opened up my Plus/4 and installed the JiffyDOS chip. For those of you without a soldering iron, you'll like this. Maurice has already installed the on-off switch for you, on both the computer chip and the drive chip. All you have to do is replace the actual Kernal chip, which should be socketed, then drill a small hole and mount the on-off switch. For Beta testing, I simply pushed the switch out of the case through the userport opening and left it lay behind the computer.

Now, the load times for a stock +4/1551, and a JiffyDOS +4 with JiffyDOS 1541:
Hitchhiker's Guide: 30 sec on 1551, 52 with JiffyDOS
Saboteur: 54 sec on 1551, 19 with JiffyDOS
General Ledger: 32 on 1551, 18 with JiffyDOS
Superbase: 59 on 1551, 59 with JiffyDOS

Compared to the standard +4 with 1541, JiffyDOS on both the computer and the drive speed up load times considerably. The 1551 now seems slow, with the exception of Hitchhiker, so I'll redo that test on Sunday.

My initial impression is that a JiffyDOS-equipped Plus/4 and 1541 are superior in load times to the standard Plus/4-1551 combination we've all held as the previous "best". If GEOS and certain demos weren't a factor, I would seriously consider selling my 1551s.

Now, moving on to the C16 software.... I find a few problems. Commercial C16 software runs so tight on memory that JiffyDOS chokes, due to JiffyDOS allocating a 255 byte buffer at the top of BASIC RAM when a disk-related command is execured. Plus, the tape routines are completely disabled when the JiffyDOS ROM is active.

I've found a few other bugs as well. One traces back to the original C64 and 128 code from 1989 or before, and Maurice feels a complete rewrite of the code would be required to fix it. The other bugs I found, he will check into when he returns to the office next week.

PAL compatibility has not been proven yet; a certain member of our group who shall remain anonymous (Hi, Mister Sunglasses in Italy!) has been selected for that job.

But I did hear a rumor (ok, rumour, thank you Lando) that 1541s on Ebay.uk are going to go up in price, so you might want to grab one or two now.

... and I had a problem near the end of my tests this evening. I was writing a bug report to Maurice when I heard a popping noise from the Commodore desk where the Plus/4 sits. I looked over in time to see a flash from the master cable that powers the Plus/4, monitor, and disk drive. I quickly shut off the power, but had to wait about 20 minutes for the 1551's step-up transformer to cool down enough to touch.... hopefully the equipment is still okay, but I think I'll wait til morning to go through it.

It's my fault, I was talking to Commodore16.com's Chris Snowden while doing this beta testing and I wasn't paying attention to what I was doing -- and plugged my 1551's 240 volt power cord into my 110 volt 1541. It only took three hours for the master power cable to overheat. Luckily enough I have more Plus/4s and 1541s just in case I toasted these. The 1551 wasn't attached to anything when this happened so I know it's OK.

I'll post more as I learn it.....

Posted By

Chris
on 2006-02-26
06:01:13