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Well I found another Prototype....iisi

MrFahrenheit

Well-known member
I don’t know if you’re posting old photos or not, but you need to immediately remove that Maxell battery. They are known to spontaneously explode, sometimes in peoples hands while removing them! I’ve heard of them exploding during shipping from a seller to a buyer.

On another note, did you manage to take a photo of the ROM SIMM in your prototype IIsi?
 

jajan547

Well-known member
I don’t know if you’re posting old photos or not, but you need to immediately remove that Maxell battery. They are known to spontaneously explode, sometimes in peoples hands while removing them! I’ve heard of them exploding during shipping from a seller to a buyer.

On another note, did you manage to take a photo of the ROM SIMM in your prototype IIsi?
I haven’t yet but I will later today looks to be normalish looking. Oh and that Maxwell has been removed and the board recapped. Power supply still smells like fish but those caps are on the way.
 

Performa450

Well-known member
Ah yeah, I saw this - you got it from the seller with the Spike PVT, right? I wasn’t sure it was a prototype from the pics, cool that it is and looking forward to more photos.
 

jajan547

Well-known member
Ah yeah, I saw this - you got it from the seller with the Spike PVT, right? I wasn’t sure it was a prototype from the pics, cool that it is and looking forward to more photos.
Yeah that guy had a ton, and yes it is a PVT but nothing crazy special sits like a late prototype with a weird EGRET, everything else seems mostly a standard.
 

Trash80toHP_Mini

NIGHT STALKER
On the PVT IIsi that you have that had a 25mhz CPU . . .
On that subject, I haven't seen you post the spec on its system Clock? Is it 40MHz in support of the full IIsi system as designed or 50MHz in order to support the faster CPU that happened to have been installed when assembled?
 

jajan547

Well-known member
On that subject, I haven't seen you post the spec on its system Clock? Is it 40MHz in support of the full IIsi system as designed or 50MHz in order to support the faster CPU that happened to have been installed when assembled?
Let me make a 7.5.5 BlueSCSI image and open TattleTech. I'll also post that ROM Picture for you @MrFahrenheit.
 

jajan547

Well-known member
Here's a Photo of a normal PDS adapter and the PVT adapter pay attention to the 343S1027's and the backs of the boards, I'll do some testing in a bit but the IIsi power supply is still not recapped and it's iffy sometimes it works sometimes it doesn't (YES CAPS are on the way). Also I added a photo of ROM Simm.
 

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Trash80toHP_Mini

NIGHT STALKER
343S1027 Bus Transceivers are a bit interesting on both cards you have. My adapters have TI Logo'd (M) (c)Apple parts. Hadn't realized they were off the shelf Programmable Logic components? Curiouser and curiouser . . .
 

Trash80toHP_Mini

NIGHT STALKER
Not strange at all, you don't stop production because you're temporarily out of stock of a spec'd, less expensive CPU and you certainly don't hold up building a prototype, if you have a 25MHz part on hand that's what you use, works just fine at 20MHz.

LEM-Legend about the IIsi being planned as a 25MHz machine, then underclocked for marketing reasons was an errant conclusion jumped to from reports of successful overclockings and use of parts shared in common with the IIci.

Given the PDS/NuBus expansion flexibility if the IIsi and system clock rate dependency for NuBus Adapter's 10MHz clock, it's clear the IIsi was designed from the ground up as a 20MHz machine.

Shades of the RoadApple 6200 LEM-Legend. :rolleyes:
 

Melkhior

Well-known member
Here's a Photo of a normal PDS adapter and the PVT adapter pay attention to the 343S1027's and the backs of the boards
Fascinating. Between the two boards, it seems all the serial capacitors mentioned in DCDMF3 are gone - only the resistors are left. The markings on the resistor packs on the back (big yellow package) aren't readable in the picture, are they readable on the real thing?

On the front side, they have different packs of resistors on the NuBus line (the three yellow or black packages on the top right). The three yellow packs are SOMC1605 271/471G packs from Vishay, so 270 Ohms to one line and 470 to the other (one is likely +5V the other ground, not sure which is which from the pictures). The other adapter in the same picture only has '8940' and '143J ' markings, the first is a production date and the second I couldn't trace. I've seen pictures with CTS packages (greenish grey) labelled 767165171A, those are 767-series of the same value as the Vishay parts (270/470). But the Radius adapter that @Trash80toHP_Mini posted in Project30 - fourth edition has '9145' and '8j08' markings from BI - they are likely to be TT Model 628 packs, similar packs but with a lower resistance of 220/330 ohms.

The 343S1027 from their size and some tracks and the IIci/IIcx schematics are likely just drivers, consolidated replacements for the set of 8x 74ALS651 in e.g. the IIcx. They need 8 as they have 4 (4x8bits per chip == 32 bits) for data and 4 for addresses to connect the split address/data bus of the '030 on the multiplexed AD line of NuBus. Each 343S1027 replaces 4x 74ALS651, 2 on each side, so they can multiplex 16 lines with less board space. 74ALS651 aren't made anymore and I have never found a "standard" equivalent to 343S1027 (from Harris or anyone else), but I suspect 74ABT651 would do the job just as well.
 

unity

Well-known member
A bit of thread necro here... but wondering if you have an pics of the back of the case? I currently have a DVT IIsi case w/mobo. The mobo does not appear significantly interesting other then -02 designation with -01 ROMs. The EGRET I will picture below cause there seems to be some fascination with it. Also a pic of the back of my case, which shows that once there may have been a second NuBUS opening in back allowing two cards to have external access versus just one when using the riser card. Just wondering if your has the same. And my case does lack the name plate moulded into the case on the bottom. Unlike yours though, my upper case was never stamped with a badge.
 

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jajan547

Well-known member
A bit of thread necro here... but wondering if you have a pics of the back of the case? I currently have a DVT IIsi case w/mobo. The mobo does not appear significantly interesting other then -02 designation with -01 ROMs. The EGRET I will picture below cause there seems to be some fascination with it. Also a pic of the back of my case, which shows that once there may have been a second NuBUS opening in back allowing two cards to have external access versus just one when using the riser card. Just wondering if your has the same. And my case does lack the name plate moulded into the case on the bottom. Unlike yours though, my upper case was never stamped with a badge.
I’ll take some of mine right now. But that EGRET is odd. The case looks right for a DVT stage but what's odd is the ROMs are soldered my best guess is this is a very late updated model they were planning maybe? Maybe plans for something like in the 6400 with a split riser in an updated EVT stage but they canceled that idea and this was some weird reboot case? Anyways I'm interested in it if it's for sale or something you'd trade.
 

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unity

Well-known member
So it is like our cases are reversed. Your board appears to be more DVT not PVT in a PVT case. Because the ROM is socketed. Yet it is in -04 board, which I also have one hand but it has soldered ROMs and is def a production unit. My board could be PVT but in a DVT case. Also the EGRET on mine, sure it means nothing but its odd the chip label is 180 of yours and production. I know that probably means nothing, but most cheap makers seem to be consistent in how they stamp things so they are orientated on the boards correctly. Just something silly I noticed. A pic of the ROMs is below. I do have it listed on eBay actually, which includes more pics.
 

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jajan547

Well-known member
That's so odd even looking at chip date codes none of this makes sense I guess maybe they had separate teams with different plans and who's ever design was cheaper and more efficient won. Or maybe it was for a team developing the network interface or something and they had an odd case. Then again it could just be a spare case they threw a test board in. The ROMs on yours are definitely stock. Mine was missing the ROM Simm and the SCSI drive was dead. Either way super cool. I saw you had it listed, if you are interested I can offer some unique items for trade if you'd like to PM me.
 

unity

Well-known member
Thats the issue, too often these machines end up on other projects and stuff gets swapped. I have a few IIcx prototypes. One was 100% original with an Avanti motherboard. But a couple others, including one I still have, was hard to be 100% certain about. One fore sure was a PVT case but a production board inside. They all came from the same Apple engineer. So there is that too, some of employees would certain take stuff home and swap it around too. I guess that is the nature of test equipment. As for trades, I am selling pretty much all my stuff so I am trying not to collect more right now. I want my collection to get down to just a few machines, mostly the compacts.
 

Arbee

Well-known member
The 0100 Egret is normal for early production IIsi machines. That’s Egret 1.0. The more common 0850 and 0851 are both 1.01 in their internal version number, it’s unclear what the differences are.
 
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