Zxpand+ a review

Any discussions related to the creation of new hardware or software for the ZX80 or ZX81
Post Reply
Moggy
Posts: 3328
Joined: Wed Jun 18, 2008 2:00 pm

Zxpand+ a review

Post by Moggy »

Zxpand+ My quick review.

For the record this prototype has been running 24hrs non stop for the last 10 days on my test rig zeddy running a variety of tests of my own creation such as 24hr read/write to the SD card every 2 seconds combined with WAV's playing through the AY unit, some GIVE-THE-RAM-A-GOOD-KICKING tests (yes it will store all the digits of factorial 5000 :lol: ) plus a few more to test timings between the various bits and bobs on the board alongside some tests Charlie requested,because I'm retired I have ample time to monitor it through the day and so would catch any faults early on and in 10 days constant running there have been 0 glitches/crashes.

I prefer not to go into too much detail re my testing methods as past experience has taught me that it usually leads to questions such as, "Why not do this? or "Why didn't you do that?
So I kindly ask that you take it on trust that this is one well hammered "Spand" :D

The inbuilt AY is just as noise free as the previous AY unit(from a S/N point of view) and MY personal observation of it is that the stereo landscape is from the "George Martin Beatles LP" school of stereo, IE 2 channels panned hard left/right with not enough of each others signal in the opposite channel as good stereo should be.
If you don't think that matters then feel free to compose something using the ZX tracker; with the centre and left channels playing a nice melody and the bass through the right channel, now crank your Akai up near full and let me know how much of your right Wharfedale laser survived after 5 minutes of basso continuo,balance being the thing. ;)

I'm an old school composer who uses 2 AY units in my studio set-up alongside real instruments so possibly am more attuned to the stereo balance on the spand, it is certainly not a criticism of Charlies work or call for it to be altered and the lads from the world of chip tune composition seem to like working that way with AY and to none musicians who just want AY as a player it should be no problem,just an observation nothing more so C'est la vie. :D

At this time of writing it's currently engrossed in a chess game at correspondence level so I envisage several more days continuous running hopefully with no problems.

None of the chips run hot,the edge connector seems a nicer tighter more solid fit than the previous spand but that may be just this prototype I hope that's not the case as this connector makes it more stable from a white-out point of view.

The physical look is in my opinion superb with its purple livery though I understand only the prototypes will be this colour.
The LED's are wonderfully bright on this board and I include a picture taken in the dark during first switch on.

I think the Zxpand+ is a worthy development and heartily recommend it to my fellow zedders and feel proud to have been allowed the chance of beta testing this wee beastie.

How it will perform on your 81's I cannot speculate as that is down to your particular set-ups power supplies other factors etc but the above is an honest review of how it performed/is performing for ME.

One final note: I notice a lack of jumper pins so as to facilitate ZX80 use so maybe Charlie could clear that one up for us at some point.
Attachments
LED.JPG
(607.22 KiB) Downloaded 541 times
User avatar
1024MAK
Posts: 5189
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Zxpand+ a review

Post by 1024MAK »

Moggy wrote: Mon Mar 27, 2017 9:44 pm Can you delete the one in the other thread (MY NEW BABY)please Mark?
Yep. I will replace it with a link to this thread.

Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp

:!: Standby alert :!:
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer being good this year.
Moggy
Posts: 3328
Joined: Wed Jun 18, 2008 2:00 pm

Re: Zxpand+ a review

Post by Moggy »

Much appreciated mark. :D
User avatar
1024MAK
Posts: 5189
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Zxpand+ a review

Post by 1024MAK »

Nice review Moggy :D

Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp

:!: Standby alert :!:
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer being good this year.
sirmorris
Posts: 2811
Joined: Thu May 08, 2008 5:45 pm

Re: Zxpand+ a review

Post by sirmorris »

For the record I will probably stick with the traditional red/green LED duo for the production boards - the disco-flavoured pink & blue were only because I was feeling frisky when I built this one lol. I'm open to discussion though.
Moggy
Posts: 3328
Joined: Wed Jun 18, 2008 2:00 pm

Re: Zxpand+ a review

Post by Moggy »

@ Mark

As yours is an opinion I have always respected and trusted in the past Mark,thanks for the kind words much appreciated. :D


@Sir Morris

NORMAL RED/GREEN LED's!!!???

NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO(takes a breath)OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!!!!!!!!

Repeat after me 1000 times.

"I will fit the ultra bright pink & blue led's only as retinal blindness is so much fun" :evil:
User avatar
Fwapp
Posts: 152
Joined: Mon Jun 01, 2015 10:32 pm

Re: Zxpand+ a review

Post by Fwapp »

Great review Moggy - can't wait to upgrade when I finally get one of the 8th batch (having been beaten to the others :D )

Would you be happy to share your ZX81 testing/thrashing program? Sounds very useful in shaking down repaired Zeddies :)
ZX80, ZX81 - 2C158C Bugged Rom iss.1, 2C158C "kludge fix" iss1, 2C184E iss1, 2C210E iss3, US NTSC iss1 "straight traces", US NTSC iss3 TS1000
Moggy
Posts: 3328
Joined: Wed Jun 18, 2008 2:00 pm

Re: Zxpand+ a review

Post by Moggy »

Fwapp wrote: Fri Mar 31, 2017 9:14 pm Great review Moggy - can't wait to upgrade when I finally get one of the 8th batch (having been beaten to the others :D )

Would you be happy to share your ZX81 testing/thrashing program? Sounds very useful in shaking down repaired Zeddies :)
Hi Fwapp.

I didn't use one program in particular and the methods I used were not to test the zeddy in any way whatsoever but rather the various bits of the xpand and rather than bog this thread down I'll PM you if you like and describe some of what I though was necessary alongside Charlies testing requests.
User avatar
Fwapp
Posts: 152
Joined: Mon Jun 01, 2015 10:32 pm

Re: Zxpand+ a review

Post by Fwapp »

Hi Moggy - yep that'd be great, thank you :)
ZX80, ZX81 - 2C158C Bugged Rom iss.1, 2C158C "kludge fix" iss1, 2C184E iss1, 2C210E iss3, US NTSC iss1 "straight traces", US NTSC iss3 TS1000
Moggy
Posts: 3328
Joined: Wed Jun 18, 2008 2:00 pm

Re: Zxpand+ a review

Post by Moggy »

Fwapp wrote: Sat Apr 01, 2017 2:05 pm Hi Moggy - yep that'd be great, thank you :)
PM sent.
Post Reply