Huge IBM 1800 find (and need some help)

Johannes Thelen johannesthelen at
Sat Mar 21 13:47:41 CDT 2015

Thanks Jon for tips!

No, that is not option, I mean 2311 is have to get back to life ;)  I think use ultrasonic or carbon ice cleaning for 2311 and disk packs. Both are quire gentle cleaning methods. I like to dump core and all disc packs for future uses ( = make original configuration).
I noticed too there is wire warppibgs at back, but can assemble gate arrays back to their places after stair case, so those are not rolling all around in truck.

I agree, I can't see why CPU would weight almost ton.

- Johannes ThelenFinland
Before microcomputers blog (Finnish)

> Date: Sat, 21 Mar 2015 13:25:39 -0500
> From: elson at
> To: General at; and Off-Topic Posts cctalk at
> Subject: Re: Huge IBM 1800 find (and need some help)
> On 03/21/2015 12:02 PM, Johannes Thelen wrote:
> >   I supposed there is some big 380/220VAC transformer somewhere.
> A quick look at the FE manual seems to indicate it uses a 
> bunch of "medium power converters"
> which seem to be modular transformer/rectifier/regulator 
> type supplies.  I think these are made
> to pull out fairly easily as field replaceable units, so 
> that might get the weight down.
> I also looked in some 360 docs and they had wildly different 
> weights listed for the same box in different 
> configurations.  This makes me think these are NOT weights 
> of individual cabinets but total system weights in different 
> configurations.
> Clearly, the machine in your picture is a larger 
> configuration with a number of cabinets added to the CPU box.
> > So, my only plan is now to get small items first, make better plan how to disassemble cabinets. Of course I have to label everything and take photos, but I'm sure something could (and surely) forgot... Disassembly is not that bad, power sources out, gate arrays can be removed releasing connectors and hinges.
> I'd be very careful about removing "gates".  There will be a 
> LOT!!! of wires, and the wire-wrap side of the boards are 
> pretty fragile. (This is an SLT machine, build much the same 
> as a 360, so I know a fair bit about how those are put 
> together.  The gates are not going to be very heavy, it may 
> be much better to leave them in place.
> The disks are probably ruined from dust accumulation, and 
> these disk drives likely have metal (not ceramic) heads, and 
> will require a lot of work to get running again.  I think 
> these use the same scheme as the 2314, with hydraulic head 
> positioners.  They will almost certainly have to be rebuilt 
> completely.  I'd clean the tops of the drives carefully 
> before opening the lids, and try to be very careful to not 
> get any more dirt in there when removing the packs.
> it may be a fool's errand to try to get the 2311 drives to 
> ever work again, possibly a fairly simple device could be 
> built that emulates the signals.  The 2311 and 2314 
> "protocol" is extremely simple.
> Jon

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