I probably have one in a box but for reference I will use the PDFs.

On Mon, 20 Oct 2025 14:46:40 -0400 Dan Greiner <[email protected]> wrote:

:>We ancient fossils fondly remember the "IBM System/360 Reference Data" 
(X20-1703), better known as the green card ... a 12-panel folded document that 
summarized the instructions, mnemonics, operands, and hardware data structures 
of the original IBM S/360. The appearance of a green  card in a shirt pocket – 
likely behind a pocket protector full of pens – identified the bearer as a true 
believer ... a programmer not to be trifled with. Over the decades as the 
architecture grew from 151 instructions to well over 1,200 in the current 
z/Architecture models, the green card grew into a reference-summary booklet (of 
varying colors) that now exceeds 100 pages. 
:>
:>In this century, IBM eschewed hard copies by (a) providing these documents in 
a PDF for free, and (b) charging outrageous prices prices for hard copy; then 
about 10 years ago, they dropped hard copy completely. For the PoO, this was 
understandable ... it now consumes over two reams of paper  and costs a bundle 
to ship. However, for the Reference Summary, this made the publication MUCH 
less useful. (I have actually printed a copy, trimmed it down to size, taken it 
to Kinko's for comb binding, and never looked at it again. )
:>
:>Since all of the information in the Reference Summary can be found in the PoO 
– and it seems unlikely that IBM will come to their senses and make hard copy 
again – it seems ridiculous to bother producing it any more. I asked the 
current editor of the documents his opinion, and he agreed that it's unlikely 
that the Reference Summary is useful any more. 
:>
:>This seemed like a great forum to solicit informed opinions. However I do 
hesitate, knowing that some will take this as an opportunity to vent their 
spleen about documentation in general.  Please don't. I simply wish to provide 
feedback to the Systems Architecture group as to whether this document is used 
in its current online-only format.

--
Binyamin Dissen <[email protected]>
http://www.dissensoftware.com

Director, Dissen Software, Bar & Grill - Israel

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