I have three (green, yellow, white) here on my desk and use them often.
The PDF is appreciated (quickest way when I need more detail), but the lack of hard copy is truly annoying. It's not like THIS one in printed form is killing trees or costing company cash. Compared to other printed doco these are truly tiny. Get a clue, IBM.
-- R; <>< On 10/20/25 2:46 PM, Dan Greiner 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.
-- -- R; <><
